Matchday dates
Listed below are the group-stage matchdays by date, plus accommodation booking links and suggestions for each game.

Alternative options:
In case the host city rates are already too high for you, I've also listed an out of town option that you could try. In each case there is a direct rail link. The times I've shown are from main station to main station using local or regional services, not express trains that are excluded by some rail passes like the Deutschlandticket. If you have an Interrail pass, however, you can use express trains, so could reach the out-of-town locations faster.
 

MATCHDAY 1: 17 June, Belgium vs Slovakia

Kick-off: 18:00
Venue: Frankfurt
Stay: Hotels Hostels Campsites Holiday homes

Hotel suggestions:

Flemings Hotel Frankfurt Central 
Stayed in by Liverpool and Union fan John for an Union away game against Eintracht a few seasons ago. Described by him as “OK” and picked largely due to its location: directly opposite the main station (and thus also the adjacent FlixBus coach station).

Adina Apartment Hotel
A tip from another Union fan, Felix, this centrally located 4-star hotel is just an 11-minute walk from the main station and about the same to the Römerberg. By public transport it's just over half an hour to the stadium.

Lindner Hotel Frankfurt Sportpark
(Part of JdV by Hyatt). Directly across the road from the stadium. 3-star hotel. Modern design. 24-hour front desk. Restaurant and bar. Free Wi-Fi. 11 minutes on foot to the Stadium S-Bahn (suburban train) station, from which the airport is a 5-minute journey and Frankfurt main station a 9-minute ride.

Hostel suggestions:

Five Elements Hostel Frankfurt
If you don't mind being in the red light district, this inexpensive hostel is handily located only 200m from the main station. 24-hour reception and breakfast buffet served up until noon.

a&o Frankfurt Galluswarte
A 20-minute walk or just one stop on the S-Bahn (metro) to Frankfurt main station (and thus the adjacent FlixBus coach station). Single, double and shared rooms. 24-hour reception. Rooftop bar.

a&o Frankfurt Ostend
Located, as the name suggest, in the east end of Frankfurt, this hostel is a 24-minute tram ride from the main station. Designed in a&o's 'next generation' style, it offers single, double, family and shared rooms. 24-hr reception. Free Wi-Fi.

Campsite suggestions:

Campingplatz Maaraue
Near Mainz. From the campsite it's 1000m to Wiesbaden-Mainz-Kastel station, then 26 minutes on the train to Frankfurt Hauptbahnhof. See Deutsche Bahn website for train times and tickets.

Campingplatz Mainkur
1400m to Frankfurt Mainkur Bahnhof (station), then a 31-minute journey to Frankfurt main station.  See Deutsche Bahn website for train times and tickets.

Holiday home suggestions:

Cozy apartment in the heart of Frankfurt
Newly renovated apartment with two bedrooms and a living room that can also be used as a bedroom. Located in Frankfurt am Main Süd, adjacent to the Sachensen cider tavern district. 10 minutes by car to the stadium. Frankfurt Lokal metro station nearby.

Lovely apartment in Brentanopark
Located to the northwest of Frankfurt city centre, this apartment in Brentanopark has two bedrooms and sleeps four. In some designated areas, smoking is allowed. 20 minutes by car to the stadium or 45 minutes by metro and tram. Rödelheim metro station is a 10-minute walk away.

Zum Kelterhaus, Ober-Hilbersheim
If you can read German, then I can personally recommend this place, as I made it my base for the 2006 World Cup. Lovely farmyard-style apartment over two floors in a sleepy village around 45 minutes' drive out of Frankfurt.

Alternative locations:

Frankfurt rates too high? Try Darmstadt instead (17 minutes away).
For other options, all within the match ticket 36-hour free travel area, see my Transport networks page.
 

Travelling to match 2 by train? Here are the Frankfurt to Cologne times and fares (for train times and fares between all host cities see my 'Train times' page).

MATCHDAY 2: 22 June, Belgium vs Romania

Kick-off: 21:00
Venue: Cologne
Stay: Hotels Hostels Campsites Holiday homes

Hotel suggestions:

Hotel Maritim
“I like Cologne, because it’s easy to walk to most places and has plenty of bars”, says Liverpool fan John. “I stayed in Hotel Maritim, which is very nice and conveniently located.”

Wyndham Köln
While the Maritim is located directly outside the front of the station, the Wyndham is right outside the rear doors. Bristol City fans Liz and Dave, who have stayed at both, preferred the Maritim, but say the Wyndham was also "a very good location if you're travelling by train".

Meininger Hotel Köln West
Budget accommodation just a 20-minute walk from the stadium. Single, twin, triple, quadruple and dormitory-style rooms available. 24-hour front desk, bar and free Wi-Fi. 

Hostel suggestions:

Station - Hostel for Backpackers
It's been many years since I was a backpacker staying in hostels, so I can't vouch for this place personally. But it certainly looks convenient, being only 150 yards from the main station (and therefore also from the cathedral and city cente).

Die Wohngemeinschaft
The name is German for 'The flat-share' or 'Communal living'. It's 19 minutes on public transport or a 30-minute walk to/from the main station. A 20-minute direct tram ride to the stadium. Rated 'Superb' on Hostelworld. Has its own cafe/bar.

a&o Köln Hauptbahnhof
Less than 5 minutes on foot to the main station. A former hotel, acquired by a&o and remodelled as a hostel / budget hotel in 2016. 24-hr reception and own bar.

Campsite suggestions:

Camping Stadt Köln
1500m walk to Heinrich-Lübke-Ufer station, then 21 minutes on the underground to Cologne main station.

Camping Berger
950m to Uferstr., Köln-Rodenkirchen bus stop, then a 9-minute bus ride to Rodenkirchen and 24 minutes by underground to Cologne main station.

Holiday home suggestions:

Pretty apartment in Bergisches Land
Located in the village of Overath about a 30-minute drive from central Cologne, this holiday flat is on the upper floor and loft level of a detached house on the edge of a nature conservation area. Wooden floors, spiral staircase, balcony and countryside views.

Apartment between Bonn and Cologne
Located in Bornheim Walberberg, between Cologne and Bonn, this self-contained apartment is an 8-minute walk from a tram stop linking you to central Cologne. 2 bedrooms. Terrace. Easy access from the main Bonn-to-Cologne road.

Complete apartment between Cologne and Düsseldorf
Located in Monheim, between Cologne and Düsseldorf, this complete apartment is just over 30 minutes by car from both the RheinEnergie Stadion in Cologne and the Merkur Spiel-Arena in Düsseldorf. Two bedrooms. Free Wi-Fi.

Alternative locations:

Cologne rates too high? Try Bonn instead (20 minutes away).
For other options, all within the match ticket 36-hour free travel area, see my Transport networks page.
  

Travelling to match 3 by train? Here are the Cologne to Stuttgart times and fares (for train times and fares between all host cities see my 'Train times' page).

MATCHDAY 3: 26 June, Play-off winner B vs Belgium

Kick-off: 18:00
Venue: Stuttgart
Stay: Hotels Hostels Campsites Holiday homes

Hotel suggestions:

Motel One Bad Cannstatt  
Affordable luxury, says the website. 24-hr reception, free WiFi. Paid-for underground parking. Just under 30 minutes to the stadium on foot or 18 minutes on public transport.

B&B Hotel Bad Cannstatt
Also within walking distance of the stadium (25 minutes). Air-conditioned en suite rooms. Free WiFi. Some on-site parking. Buffet breakfast at extra cost.

Premier Inn Bad Cannstatt  
Familiar Premier Inn accommodation 3 miles from the main station and 1.6 miles from the stadium, which Google Maps says you can walk to in 37 minutes or reach by car/taxi in 7. 

Hostel suggestions:

Jugendherberge Stuttgart Neckarpark
Youth hostel with single, twin, triple, quadruple rooms and dorms. Bar. Free Wi-Fi and free parking. A 20-minute walk to the stadium. 4 minutes to Bad Canstatt S-Bahn station, from which it's a 4-minute ride to the main train station.

Jugendherberge Stuttgart International
A 15-minute walk to the main station and 25 minutes by bus to the stadium. 309 beds in 94 rooms. 24-hr reception. Free breakfast and Wi-Fi. IYHF membership required.

a&o Stuttgart City
5 minutes on the underground to/from the main station. 30 minutes by bus and underground to the stadium. 24-hr reception and bar. Rooms range from singles to 8-bed dorms. Free Wi-Fi.

Campsite suggestion:

Camping Canstatter Wasen
15-minute walk from the ground.

Holiday home suggestions:

Modern apartment in city-centre listed building
Just a 12-minute walk from the main station, this spacious modern apartment on the first floor of a listed building dating from 1889 is decorated throughout in white and sleeps up to 6. Two bathrooms. Balcony overlooking garden. Rated 'Exceptional' by reviewers on Vrbo.

Luxury apartment in Kornweststein
Located to the north of central Stuttgart in the Kornweststein district, this luxury apartment is just a 2-minute walk from the nearest suburban train station, from which it takes just 12 minutes to get to the main station in Stuttgart. Two bedrooms. Sleeps 4. Modern furnishings.

Modern apartment in Waiblingen
A little way out of Stuttgart, which is reflected in a lower price. Yet, the nearest suburban train station is only an 8-minute walk away and the journey into town only 18 minutes. Two bedrooms. Sleeps 4.

Alternative locations:

Stuttgart rates too high? Try Ludwigsburg instead (15 minutes away).
For other options, all within the match ticket 36-hour free travel area, see my Transport networks page.

Group-stage base:

For a potential group-stage base away from the host cities, see my Group D Base page.