Dusseldorf

The city amassed a vast number of works by these and other 20th- and 21st-century artists; the collection is so large, in fact, that it’s housed in two separate museums, K20 and K21. — Time Out

a nearly mile-long promenade brimming with high-end designer boutiques including Chanel, Louis Vuitton, Cartier and Ferragamo. — Time Out

This impressive art museum lies at the northern extremity of the Hofgarten, close to the Rhine. — Fodor's

On the northern edge of the Hofgarten, this modest museum dedicated to the great man of letters is housed in the pretty-in-pink 18th-century Schloss Jägerhof on the park's northern edge. — Lonely Planet

When you've had your shopping fill, head on over to the pleasant Hofgarten dotted with statues of Heinrich Heine, Robert Schumann and other German greats. — Lonely Planet

The rooms in the main castle are sumptuously decorated with enormous chandeliers, opulent frescoes, marble floors and statuary galore. Some furniture is still original to the palace. — Time Out

This museum and archive houses significant manuscripts of the German poet and man of letters, Heinrich Heine. — Fodor's

A squat tower is all that remains of the palace built by the Berg family, which ruled Düsseldorf for more than five centuries. — Fodor's

Devoted to the evolution of humanity and relates the life of prehistoric man. Modern techniques have enabled the museum staff to faithfully reproduce what our ancestors looked like. — Michelin Guide

Situated on the banks of the Rhine, Düsseldorf's old town is known as "the longest bar in Europe", thanks to its many bars and taverns. — Michelin Guide

Aachen's town hall sits behind the Dom, across Katschhof Square. — Fodor's

The buzzing neighbourhood of Medienhafen offers a comprehensive overview of contemporary architecture. — Michelin Guide

Great place for photographers that want to catch astonishing pictures of unusual places. — Afar Magazine

Spearing the sky at the southern end of the Rhine promenade, the Rheinturm (which is brilliantly lit at night) has an observation deck at the 168m level of its overall height of 240m. — Lonely Planet

Young artists – many from the local art academy – get the nod in this underground exhibition space housed in a spectacularly adapted tunnel below the Rheinuferpromenade. — Lonely Planet