In Italy I believe the 70% of times you start to dig for a building you find something archeological interesting. Interesting mainly to be studied and only sometimes to be exposed. So, if we should show everything found in the original position will be almost impossible build or restore. This happens everywhere in Italy.
Some examples from my area:
- in Modena there is a car seller with some late Roman empire graves in the middle of the show room, founded during restoration.
- in Modena 10 years ago during the construction of a new underground parking area found ruins and archeological things of the previously 2000 years. The roman road and graves has been moved at the ground level and rebuild as they were during the early Roman Empire. Some ruins too has been moved to the ground level, while all the other graves and skeletons has been moved to the museum to be studied. The pottery deposit is shown at the first underground floor. So a normal and commercial car parking lot has been build and the park over it became an archeological area: a win-win solution both for the owners and the citizens of Modena.
- in Bologna some years ago has been found the level of the ancient "Via Emilia". That one unfortunately cannot be exposed because under one of the main central street: after the studies has been covered again and last there for other 2200 years.
- in Bologna one of the roman road can be visited in the underground of the best hotel (in front of the bathroom! :-D ). Even the ruins of a theatre are under a commercial building.
A lot of ancient things found underground are very interesting for studies and to better know something about the ancient world, but few ones are so nice to be exposed in museums, even small local museums. So sometimes is better leave the things where they are and make that they became a little oddity/curiosity for other places.