The typical Estonia manor house (mõis) that is visible in the landscape of Estonia was the home of a titled Baltic German landlord and family. The Baltic Germans at the height of their power in the late 19th century had split the entire land-holding of Estonia into two thousand estates of which 1245 were main manor houses, 600 were dairy manor houses and 108 were were church manors - see Valdo Praust's wonderfully extensive Estonian Manors website The Enlish language pages show 400 manors, the Estonian language pages show 700.
13th century architecture exists in the shape of the castles built by the Teutonic Order and the Bishoprics of Dorpat, Ōsel-Wiek and Reval. None survive wholly intact, except perhaps for the Bishop's Fortress at Kuresaare. The most iconic of Estonia's castles, Narva Castle, appeared on the unique post-1991 5 kroon note because it was on the left bank facing across the international border a foreign (e.g. Russian) castle, Novgorod (on the right bank).
The templates of the surviving manor houses are culturally diverse - Suuremoisa on Hiiumaa is based on a Swedish Palace, Alatskivi in Tartumaa close to Lake Peipsi is based on Balmoral in Scotland, Muuga in Laane-Viru is built in the style of an Italian villa and the monumental Taagepera is clearly influenced by Germanic architecture. Most of the surviving examples were built in the late 19th and early 20th centuries, replacing older buildings on the same sites. The vast majority were constructed of bricks and mortar and like Sangaste look solid and robust. Considering that the use of wood to construct the buildings in Tartu led to the city burning down 7 times, wooden manor houses that have survived are rare as is Kukulinna on the shore of Saadjärv, which is now privately owned.
Those manor houses that survived Estonia's War of Independence (1918-1920) and the transfer of landownership from Baltic Germans to Estonians were largely saved by the state taking them into public ownership and using them as schools, such as Puurmanni, sanatoriums, spas and homes for the elderly.
Soviet occupation forces between 1944 and 1991 either maintained the manors' uses as state institutions, or organs of the communist party used them, like Komsomol did at Sangaste and also at Alatskivi.
In 1991, German baronial families who'd fled the Soviet advance in 1944 and could prove ownership were able to apply for restitution of their properties but not their estates. This happened, for example, at Kolga in Harjumaa, but the owners do not have sufficient finances to restore the house to its former glory. Most of the manors however became the properties and responsiblities of the counties and parishes in which they are located. Rather than lose their capital on maintaining these manorial properties, a great many were sold into corporate ownership for use as spa hotels. Invariably the spa hotels have been bankrupted by global economic crises and as has happened at Kalvi have now passed into private ownership as luxuriously appointed homes.
A few of the surviving manor houses have followed the museum model (charging fees to enter) with hotels and conference centres attached, Palmse and Sagadi, while Kiltsi is basically just a museum and former home to a famous seafarer and explorer.