Budapest in 2-3 Days — Buda Castle, Thermal Baths & Ruin Bars

Practical Tips

Fisherman's Bastion: upper terrace is FREE and gives the same view as the ticket-required lower level. Walk the entire upper circuit free of charge. The lower interior arcades require ~€4 and add very little.
Matthias Church (Mátyás-templom): ~€5 adult, open for visitors most hours (closed during services — check matyas-templom.hu). The interior is extraordinary — Gothic structural bones overlaid with 19th-century Neo-Romanesque paint by Bertalan Székely. The crypt has Hungarian royal treasury items.
Funicular (Budavári Sikló): €5 one-way, €8 return. Not worth it compared to the 15-minute walk. The view from the funicular is fine but no better than the walk. Skip and walk.
Budapest History Museum (in the Castle): the most overlooked museum in the city — excavations showing the multi-layered construction from medieval fortress to Habsburg palace. €8. Allow 1.5h if interested in medieval urban archaeology.
Sunset from Fisherman's Bastion: the east-facing terrace faces Parliament across the Danube — the Parliament lit at dusk is one of the finest urban views in Europe. Timed for 19:30–20:30 in summer.