St. Olaf’s Church (Oleviste kirik) is believed to have been built in the 12th century and to have been the centre for old Tallinn's Scandinavian community prior to the conquest of Tallinn by Denmark in 1219. Its dedication relates to King Olaf II of Norway (a.k.a. Saint Olaf, 995-1030). The first known written records referring to the church date back to 1267, and it was extensively rebuilt during the 14th century.
A legend tells that the builder of the church, named Olaf, upon its completion, fell to his death from atop the tower. It is said that when his body hit the ground, a snake and a toad crawled out of his mouth. There is a wall-carving depicting this event in the adjoining Chapel of Our Lady.
Around 1500, the building reached a height of 159 meters. The motivation for building such an immensely tall steeple must have been to use it as a maritime signpost, which made the trading city of Tallinn visible from far out at sea. Between 1549 and 1625, when the spire burnt down after a lightning strike, it was the tallest building in the world. The steeple of St. Olav has been hit by lightning at least eight times, and the whole church has burned down three times throughout its known existence. Following several rebuildings, its overall height is now 123.7 meters.
From 1944 until 1991, the Soviet KGB used Oleviste's spire as a radio tower and surveillance point. It currently continues as an active Baptist church. The tower's viewing platform offers panoramic views over the old town and is open to the public from April through November.
Roman Walls of Lugo are an exceptional architectural, archaeological and constructive legacy of Roman engineering, dating from the 3rd and 4th centuries AD. The Walls are built of internal and external stone facings of slate with some granite, with a core filling of a conglomerate of slate slabs and worked stone pieces from Roman buildings, interlocked with lime mortar.
Their total length of 2117 m in the shape of an oblong rectangle occupies an area of 1.68 ha. Their height varies between 8 and 10 m, with a width of 4.2 m, reaching 7 m in some specific points. The walls still contain 85 external towers, 10 gates (five of which are original and five that were opened in modern times), four staircases and two ramps providing access to the walkway along the top of the walls, one of which is internal and the other external. Each tower contained access stairs leading from the intervallum to the wall walk of town wall, of which a total of 21 have been discovered to date.
The defences of Lugo are the most complete and best preserved example of Roman military architecture in the Western Roman Empire.
Despite the renovation work carried out, the walls conserve their original layout and the construction features associated with their defensive purpose, with walls, battlements, towers, fortifications, both modern and original gates and stairways, and a moat.
Since they were built, the walls have defined the layout and growth of the city, which was declared a Historical-Artistic Ensemble in 1973, forming a part of it and becoming an emblematic structure that can be freely accessed to walk along. The local inhabitants and visitors alike have used them as an area for enjoyment and as a part of urban life for centuries.
The fortifications were added to UNESCO"s World Heritage List in late 2000 and are a popular tourist attraction.