Brussels to Cologne
Belgium to Germany by ICE

Cologne trains leave from Brussels-Midi - Brussel-Zuid on the Dutch-language signs - Belgium's international hub, where they line up alongside Eurostars from London and Paris. Boarding the ICE is refreshingly informal: no gates, no lead time, walk up and board from the ordinary platforms like any Belgian domestic train. Most departures also call at Brussels-Nord minutes later, useful if you are staying near the EU quarter's northern edge.

Midi itself is well connected: metro lines 2 and 6 underneath, trams outside, and frequent trains to Brussels-Central in a few minutes. Connecting from London or Paris? The Cologne ICE leaves from the same station your Eurostar arrives into - a same-station change that makes London→Cologne or Paris→Cologne an easy one-stop itinerary.

The first minutes run east through Brussels' suburbs to Leuven, Belgium's great university city - six centuries of colleges around one of Europe's most ornate Gothic town halls, worth its own visit on a slower day. Some ICEs call here; others sail through. Either way, Leuven is where the journey changes character.

Just beyond the city the train swings onto HSL 2, Belgium's eastern high-speed line, and accelerates to 300 km/h across the Hesbaye - a wide, rolling plateau of wheat and orchards where the catenary posts flicker past faster than the scenery deserves. It is the fastest stretch of the trip, and it makes short work of the middle of Belgium.

From Leuven's Gothic spires to 300 km/h in about a minute - central Belgium at its most efficient.

The descent into the Meuse valley ends under one of Europe's great modern stations: Liège-Guillemins, Santiago Calatrava's soaring vault of white concrete and glass, opened in 2009. There are no walls in the conventional sense - the canopy simply pours over the platforms - and even a two-minute ICE stop is enough to understand why architecture pilgrims come here on purpose.

Liège is also the corridor's junction: this is where the Frankfurt ICEs and the Paris–Cologne axis intersect with Belgian domestic lines toward the Ardennes. Leaving Guillemins, the train climbs out of the valley onto HSL 3 through the green hills of the Pays de Herve - the prettiest scenery of the trip - aiming for the German border.

The Belgian–German border passes in the wooded hills just west of Aachen, at line speed and without ceremony - Schengen means no systematic checks, though police do board international trains from time to time, so keep your passport or ID card reachable. The first announcement in German is usually the clearest sign you have arrived.

Aachen, the first German stop, carries more history than its size suggests: Charlemagne's capital, whose palatine chapel - the core of the cathedral - has watched over coronations since the ninth century, ten minutes' walk from the Hauptbahnhof. It is also a practical interchange for regional trains across the three-country corner where Germany, Belgium and the Netherlands meet. From here the ICE drops onto the classic line via Düren for the final half hour across the Rhineland plain.

The border announces itself in the small print: the announcements switch language, the signals change shape, and Charlemagne's city rolls up to the windows.

No station in Europe makes an entrance like Cologne's. Köln Hauptbahnhof sits directly beside the Dom - step out of the main exit and the twin spires of the cathedral, Germany's most-visited monument, fill the entire view before your eyes have adjusted to daylight. It is a genuinely startling arrival, and it never quite stops being one.

The station is western Germany's great junction. S-Bahn and U-Bahn lines fan out beneath and beside it; the old town and the Rhine embankment are minutes away on foot; and the departure boards read like a national timetable - ICEs east and north across Germany, and the Hohenzollern Bridge carrying every onward train across the Rhine right behind the station.

The ICE International is Germany's flagship product doing international work: quiet, comfortable, with a restaurant car, at-seat power and generous luggage racks. Crucially, reservations are optional - board with any valid ticket and take any unreserved seat, or add a reservation for a small supplement with saver fares (flexible fares include one automatically). Boarding is walk-up at both ends: no gates, no check-in, no lead time beyond finding your platform.

Some Eurostar services also run the Brussels–Cologne corridor as part of the Paris–Germany axis, and they play by different rules: reservation-only, airline-style fares, assigned seats. They are perfectly good trains - but for flexibility, and especially for rail-pass holders, the ICE is the default choice on this route. Whichever you board, seven-ish direct services a day plus easy connections keep the corridor well served; check current timetables rather than trusting a fixed pattern.

Buy from either railway: DB and SNCB sell the same ICE trains, sometimes at different prices, so a thirty-second comparison pays. Saver fares are cheapest booked ahead and tie you to a train; flexible fares cost more and include a seat reservation. Interrail and Eurail passes make this one of Europe's friendliest borders - full coverage both sides, no supplement, no reservation needed, just walk on.

And Cologne is a beginning as much as an end. The high-speed line to Frankfurt (about an hour) makes Brussels→Frankfurt a painless half-day; the classic Rhine line south toward Koblenz and Mainz is one of Germany's loveliest everyday rides, castles included; and direct ICEs reach Berlin, Hamburg and the Ruhr from the same platforms you arrive at. Paired with Eurostar from London or Paris, this corridor is how Western Europe's capitals connect to the German network.