🇧🇬 Bulgaria · Ancient city
Solnitsata (Provadia-Solnitsata)
Late Neolithic to Chalcolithic (Karanovo–Varna sequence) · Hamangia → Varna → Gumelnița associated
Earliest prehistoric town in Europe (c.5600–4350 BCE, Late Neolithic–Chalcolithic) — fortified stone-walled (3 m thick) salt-production centre at Mirovo rock salt spring, the oldest salt mine in…