St. Bridget's, Tallinn
Saint Bridget’s nunnery was founded in the 15th century and housed both as monks as nuns. But more than century later it was destroyed by Ivan the terrible leaving from the building only some part of the façade and some walls. As it was said the stones from it were used in all Estonia. There is also legend that there is secret underground way from nunnery to city.
Pirita klooster (St. Bridget's Convent) is located near the Pirita river (no kidding!) outside central Tallinn. It was built in 1407 but destroyed by the invading Ivan the Terrible in 1577. The ruins have been standing for an amazing four centuries and counting!
It was one of the most pleasant surprises of our stay in Tallinn. We ended up walking in the ruins for almost an hour. At 20 krooni, it is one of the best bargains among Tallinn's sights.
Also, you can take a short walk from the Convent along Pirita river. You can also rent a boat at nearby Paadilaenutus Pirita jõel (located at Kloostri 6A).