Here in Devon (for a morning or afternoon out) why not try:
Sunday 13th July – Mount Folly Enclosures Project excavation open afternoon at Bigbury-on-Sea in South Devon. This is an archaeological investigation of Iron Age and Romano-British occupation of a coastal settlement. The project has been running since 2003 and has grown to be one of the largest volunteer excavations in the south of England. The site will be open from 2pm.
Sunday 20th July – Ipplepen Project excavation Open Day. This site was discovered in 2007 as a result of two local metal detectorists finding and reporting Roman coins. Subsequent archaeological investigations confirmed that the discoveries were associated with many archaeological features of Iron Age and Romano-British date lying below the ground, over an area of several acres. The site will be open from midday until 4pm.
Sunday 27th July – East Devon Heathweek Family Festival at Woodbury Castle near Exeter. The festival runs from 11am to 3.30 pm and as well as various displays and activities based around the flora and fauna of the East Devon Pebblebed Heaths, there will also be a chance to visit the late prehistoric hillfort.