Royal greenhouses, Belgium

In Laeken, a 15-minute drive from Brussels, the Royal Greenhouses (61 Domaine Royal, Avenue du Parc Royal, 1020 Brussels, Belgium) open to the public for three weeks every year, as the flowers are in full bloom. The tallest of the towering glass structures is large enough to contain full-grown palm trees.

In 2009 they are open April 17-May 10, from 9:30 a.m. to 4 p.m. Tuesday-Thursday, 1-4 p.m. and 8-10 p.m. Friday and 9:30-4 and 8-10 Saturday and Sunday. Entry, €2.50.

Contact the Brussels tourism office (phone + 32 0 70 221 021, www.bruxelles-tourisme.be).