Kadrioru lossi jääkelder
Once you visit the modern art museum, Kumu, you happen to be a stone's throw away from this lovely building; Kadriorg Palace. It was built by Peter the Great for Catherine I of Russia (1718) and later redone by Nicolas I (1827) [Wikipedia].
Thanks to all Phoide contributors to Kadrioru lossi jääkelder!
Most notably Adelheid Smitt and Rob Oo.