The Thracian tomb of Kazanlak was discovered in 1944 when soldiers were digging trenches in order to protect from air raids. They were named an UNESCO world heritage site in 1979 making it one of the earliest named at all. The original tomb was once in a mound. After its discovery, a small house was built over it in order to protect it. This original tomb is not accessible to the general public. Only scholars with permit from the ministry of culture may enter it. For some time, it was possible to peek into this tomb by looking through iron bar windows in the rear part of the house.

Just a couple metres away is an 1:1 scale replica with a short explanation about the place's history and some items discovered in the tomb.

From a historian's point of view, I can imagine that the Thracian tomb of Kazanlak has a distinctive importance since its frescoes are considered to be the best preserved of the Thracian era in Bulgaria.

From a touristical point of view, the place is fine for a fifteen minute visit (which includes walking around the original) but not more. If ticking off an UNESCO WHS is your only reason to come here, you might be disappointed. It is an incredibly tiny place. The sign asking you not to enter the tomb replica with more than four people is quite sarcastic as I can't imagine how four average-sized male visitors with a light backpack would enjoy it without feeling some kind of claustrophoby.

Although this is the only place where you can really get an impression on hand of how the original looks like, I would consider the exhibition in Kazanlak's history museum far more informative.