If you're in Portsmouth Fishbourne and Bignor are easy targets;
en.wikipedia.org/wiki/Fishbourne_Roman_Palace
en.wikipedia.org/wiki/Bignor_Roman_Villa
Chichester was a Legio II base for a while;
http://roman-britain.co.uk/places/noviom...gnorum.htm
with some of the circuit wall still standing and the local museum built on a bath house;
http://www.thenovium.org/
and Butser is good for Iron Age, with a little villa;
en.wikipedia.org/wiki/Butser_Ancient_Farm
Not very Cotswold though, more South Downs
en.wikipedia.org/wiki/Fishbourne_Roman_Palace
en.wikipedia.org/wiki/Bignor_Roman_Villa
Chichester was a Legio II base for a while;
http://roman-britain.co.uk/places/noviom...gnorum.htm
with some of the circuit wall still standing and the local museum built on a bath house;
http://www.thenovium.org/
and Butser is good for Iron Age, with a little villa;
en.wikipedia.org/wiki/Butser_Ancient_Farm
Not very Cotswold though, more South Downs