Borgund stave church, Borgund, Norway Ok, maybe it's not 'engineered', but it's nearly 1000 years old, so obviously they knew what they were doing. The church was built in the 1100's (pre-dating Gengis Khan) with post and beam construction and has never had a major reconstruction or change of structure! There are 25 or so of these ancient churches still in existance. Wood, baby.
In a mountainous region in the heart of Ethiopia, some 645 km from Addis Ababa, eleven medieval monolithic churches were carved out of rock. Their building is attributed to King Lalibela who set out to construct in the 12th century a ‘New Jerusalem’, after Muslim conquests halted Christian pilgrimages to the holy Land. Lalibela flourished after the decline of the Aksum Empire.