This massive, 38m-high cannon tower houses an extensive museum of the town's fortifications, weapons and medieval-era life. https://www.visittallinn.ee/eng/visitor/see-do/sightseeing/pid-174740/kiek-in-de-kok

Exquisite altarpieces, medieval burial slabs and other works of religious art can be seen in this 1230-era church-turned-museum. Saints, dancing skeletons and silver – not to mention the occasional organ concert – are the main attractions here. https://www.visittallinn.ee/eng/visitor/see-do/sightseeing/pid-174741/niguliste-museum-st-nicholas-church