Frontline-beach villas and resort complexes on the sea side; mountainside villa estates — Sierra Blanca, Las Lomas del Marbella Club — on the inland side. Not itself gated, though developments within it (Puente Romano, Mansion Club) are. The Marbella Club Hotel (1954) started it; Puente Romano followed in 1979; the King Abdul Aziz Mosque arrived in 1981. Roman villa remains sit near the Río Verde, next to the bridge Puente Romano is named for.
Asking prices: €639,000 to €8.5M+ in the visible Idealista sample for the Nagüeles–Milla de Oro zone; villas roughly €2.5M–€8.5M. Per square metre: €9,544/m² average asking, €9,216/m² for villas (Idealista); first-line-beach reaches €30,000/m² per the DM Properties/Knight Frank 2026 report. 1,391 homes listed on Idealista, 321 of them villas. (24 July 2026, per the sources below.)
Numbers from the linked sources, dated as marked. Asking is not getting — for what sellers actually achieve, the catalogue keeps receipts.