Founded in 1894 by Percival Lowell, the Lowell Observatory serves as a research institution, as well as a public space for astronomy enthusiasts, featuring telescopes, multimedia shows, and exhibits. The dwarf planet Pluto was discovered here in 1930 by Clyde Tombaugh.

Carlstadt is the city’s exquisite quarter of galleries and antique shops. Citadellstraße with its elegant stately residences from the 18th and 19th centuries and the flair of its streets almost unchanged since these days, seems to have escaped the passing of time. A more profound insight into Düsseldorf’s history can be gained at Stadtmuseum at the corner of Bäckerstraße and Berger Allee. Its cosy garden is treated as an insidertip! The Carlsplatz, and its lively food market open from Monday to Saturday. From here, take the attractive Bilker Straße for a visit to the Heinrich-Heine- Institute or proceed past the former residence of Robert and Clara Schumann to Bastionstraße, a must for every lover of antiques.

Düsseldorf's Altstadt (Old Town) is also home to some of the city's most beautiful churches. For instance, the Sankt Lambertus Basilika, which was first built in the 13th century, and which with its twisting spire helps make Düsseldorf's skyline unique. In conjunction with the Schlossturm (Castle Tower) and the River Düssel, the basilica remains part of the Old Town's original core. This church's parish altar also houses a shrine containing relics of Saint Apollinaris, the city's patron saint.

As one of the most beautiful and appealing caves in Ha Long Bay, Sung Sot is a dazzling work of nature, astonishingly vast in size, despite its inconspicuous appearance from the outside. The rocky entrance down into the cave, coated in dense vegetation, leads to two large limestone-laden chambers, each meticulously decorated with a millennia-old ceiling of delicately formed stalactites. The impressive rock formations are colourfully lit up and can be admired from the comfort of a smooth walking path that traverses the cave.