Found this collection of links with some archaeological datasets. It's just for UK though.
Here's a teaser
ARCHAEOLOGICAL DATA
Source – BAA, Oxford Archaeology and Wessex Archaeology.
Data – Archaeological data for Stansted and Heathrow Airports. Excavations by Framework Archaeology 1998 to 2004
Format – Various, including ESRI format.
Licence – Creative Commons Attribution-NonCommercial 2.0 License (see website).
Cost – Free.
Comments –
Link - http://www.framearch.co.uk/stansted/index.html - Stansted Link - http://www.framearch.co.uk/t5/data-downloads/ - Heathrow T5
Here are some free archaeological datasets from the Swedish National Data Service.
This one's from the La Milpa, Belize.
The Stanford Library has some links on archaeology datasets, too.