The closest beach to Doubia (Mainland Halkidiki) is Agios Mamas, 34.0 km away. Ordered by distance from Doubia. Photos, map, reviews.
34.0 km from Doubia

34.9 km from Doubia

35.3 km from Doubia

35.3 km from Doubia

35.4 km from Doubia

35.8 km from Doubia

36.8 km from Doubia

37.6 km from Doubia

40.1 km from Doubia

44.7 km from Doubia

51.2 km from Doubia

Agios Mamas, just 34.0 km from Doubia. The rest are listed below, ordered by distance.
None sit within 15 km of Doubia itself, but Mainland Halkidiki has 21 beaches in total — listed below, closest first.
Based on user reviews: Nea Moudania (★4.0), Psakoudia Beach (★3.8), Plagia-Flogita Beach (★3.8).
The beaches are spread out around Doubia. A car makes exploring much easier — local buses and taxis are limited outside peak season.
Doubia is on the Mainland Halkidiki side of Halkidiki, in northern Greece. The nearest airport is Thessaloniki (SKG); from there a car is the most convenient way to reach the Mainland Halkidiki villages.