The S-61 Delfín is a Daphné-class submarine that served the Spanish Navy from 1973 until its decommissioning in 2003, and now sits on permanent display near the harbour as a monument — a distinctly unusual sight along a Mediterranean seafront. The Daphné class was a French design built in the 1960s and 1970s and operated by several navies; the Spanish vessels were among the last of the type still in service when Delfín was retired. The decision to install it at Torrevieja rather than at a naval base reflects the town's tradition as a maritime community, and it has become one of the more photographed landmarks on the paseo marítimo.
Up close, the submarine is larger than it looks in photographs — around 57 metres long — and the hull shows the proper wear of a vessel that spent three decades in active service. Access inside the submarine is limited (it is a monument rather than a fully open museum), but visitors can walk around it, read the information panels, and get a genuine sense of the scale and form of a working Cold War-era submarine. It sits between the town's marina and the beach, making it easy to combine with a walk along the waterfront. Children tend to be fascinated by it; naval history enthusiasts will find it worth a longer stop.