The best day trips from Kerman lead either south to the gardens and shrines of Mahan (the Shazdeh Garden and the Shah Nematollah Vali shrine, both reachable in half a day) or east into the Lut Desert for sunset at the Kaluts. Both should be done by hired car or with a local tour; public transport is impractical for either.
Further afield, the ancient citadel of Bam sits 190 kilometres southeast — devastated by the 2003 earthquake but slowly rebuilt — and remains one of the most extraordinary mudbrick sites in the world. Rayen, on the way there, has a smaller but better-preserved citadel sometimes called "the second Bam". Both are long but worthwhile day trips; an overnight in Bam allows a slower visit.