I had always dreamt of visiting the great tropical greenhouses of the Botanic Garden in winter. Lush, humid air within; icy fields without: the contrast equal to a work of art.
The first thing we did on entering was to strip off overcoats, cardigans and scarves. The close, fragrant heat left our cheeks flushed. Gold carp and red carp wove through the water as we followed the stepping stones. From above, the two tree trunks measuring some twenty feet in diameter made me gasp.
The Botanic Gardens were originally designed more for scientific research than for visitors. The paths are narrow, signage is poor; the display cases are dusty and dated. If you're after a roomful of camellias in full bloom, though, you're in luck.
Did you spot the flash of orange feet above? This tiny wingless bird scurried through the papaya trees while the children watched, rapt, and I watched them, glad to be warmed through at last.
PS: Take the M48 bus to the Botanischer Garten stop if you can; from the S-Bahn station of the same name, it's a trek to the garden gates. The cafe situation in winter is dire (cramped and dim) so consider bringing a picnic to eat at the sunny tables just outside the main greenhouse.