A few kilometres south of Anzio, the Tor Caldara nature reserve protects a stretch of coastal woodland that is among the last of its kind in Lazio. A 16th-century watchtower — the tor — stands above sulphurous springs that emerge on the beach, evidence of the volcanic geology beneath the flat coastline. The forest behind it is made up of holm oak and Mediterranean scrub.
The reserve can be explored on foot along marked trails. The sulphur springs are the main curiosity: the water emerges warm and smells strongly of hydrogen sulphide, leaving orange mineral deposits on the rocks. It is not glamorous, but it is genuinely strange — and the beach here is quieter than the main Anzio resort. The reserve is managed by the Lazio regional parks authority.