Transport
A weekend by train only
Bucharest–Constanța / Tulcea, then whatever you can reach on foot or by bus. The official timetable link is CFR's. We do not scrape. Off-season, the coast is city and museum, not beach.
Bucharest–Constanța
The most frequent connection. From the station: the peninsula, Walk Ovidiu, museums. A taxi or a city bus, not a rental car because 'we're here anyway'.
Toward Tulcea
Less frequent. A base for the Delta without a car. The boat timetable is the operator's; check it the day before.
On the coast
The Mangalia train links Eforie, Techirghiol, Costinești. Autumn is good for the seafront. Summer is packed. Winter is empty and honest.
What does not fit
Histria, Adamclisi, Măcin: they need a transfer. A weekend by train only is not a weekend of every fortress.
Luggage
A backpack. A return ticket thought through. A museum plan if it rains.