Catherinethal ("Catherine's valley") is a Petrine Baroque palace of Catherine I of Russia in Tallinn. It was built after the Great Northern War to Nicola Michetti's designs by Gaetano Chiaveri and Mikhail Zemtsov. In the 20th century the Estonian version of the name, Kadriorg, gained currency and came to be applied to the surrounding district.
After the successful siege of Reval in 1710 Peter the Great of Russia bought a Dutch-style manor house at Lasnamäe for his wife Catherine. The house today is the result of a drastic renovation ordered by Nicholas I of Russia in 1827.
The new palace was started on 25 July 1718. Peter and Catherine visited the unfinished residence on several occasions, but after the emperor's death in 1725 Catherine showed no interest in the seaside property. The great hall with Catherine's initials and profuse stucco decor (attributed to Heinrich von Bergen) survives, but many other interiors have been altered. The gardener Ilya Surmin was responsible for the flower garden with two fountains and the so-called mirage garden on several levels. The layout of the park shares similarities with that of Strelna.
The palace currently houses an art gallery. The KUMU Museum is sited in the park.
Built around AD 90 to entertain the legionaries stationed at the fort of Caerleon (Isca), the impressive amphitheatre was the Roman equivalent of today’s multiplex cinema. Wooden benches provided seating for up to 6,000 spectators, who would gather to watch bloodthirsty displays featuring gladiatorial combat and exotic wild animals.
Long after the Romans left, the amphitheatre took on a new life in Arthurian legend. Geoffrey of Monmouth, the somewhat imaginative 12th-century scholar, wrote in his History of the Kings of Britain that Arthur was crowned in Caerleon and that the ruined amphitheatre was actually the remains of King Arthur’s Round Table.
Today it is the most complete Roman amphitheatre in Britain.