The newly-renovated Niguliste Kirik (St Nicholas' Church) in Tallinn is to reopen to the public Saturday.
The church, which in fact functions as a museum rather than a place of worship, has new features including an elevator and viewing tower.
The work took over a year, and was held up by a day due to permit issues.
The elevator travels up and down three floors, including the viewing platform which will allow virtually 360-degree views across the capital and environs.
Other developments include a new exhibition space.
Sirje Helme, Eesti Kunstimuuseum director, said the renovation work had turned out to be more complicated than initially expected.
"As always with historic buildings, during the course of the renovation, were many situations came to light which required a quick response and smart solutions.
"The construction process ended up a series of surprises, good and bad. However, the outcome is excellent: We now have a renovated and well-functioning building; a modern and safe home for the most valuable collection of medieval art in Estonia," Helme went on.
Funding came via the Eesti Kunstimuuseum the architectural and design work, both on the elevator and viewing platform, was carried out by KOKO, wih the tender for construction work going to OÜ Tarrest LT.
One of the museum's most famous exhibits is the Danse Macabre, by Bernt Notke (c 1440-1509), a fragment of which survives from the estimated 30m-wide original.
This and other valuable artworks had to go into storage during the renovation work.
The Niguliste kirik's spire was destroyed no less than two times in the space of 40 years; Soviet bombing during World War Two damaged the original, while a fire in 1982 came less than a year after the church had been restored - but not consecrated, given the Soviet system. For this reason many Soviet-era photos of the Old Town depict a spire-less Niguliste kirik.
Editor: Andrew Whyte, Mirjam Mäekivi