Cul de Sac - Thonglor Rooftop Bar sits on the 10th floor of The Quartier Hotel on Sukhumvit 39, a short walk from both Thonglor and Phrom Phong BTS. The concept is 1980s throwback: string lights strung across the terrace, graffiti walls, and a scattering of 80s memorabilia tucked into the decor. An open-air deck wraps around a rooftop swimming pool, and one wall doubles as an outdoor cinema screen for movie nights.
It is a rooftop bar in Thonglor, Bangkok, but the energy is closer to a neighbourhood party than a formal sky bar. The crowd is a mix of Sukhumvit expats, hotel guests, and Thonglor locals who come for the music and the pool view rather than a dress code. Cul de Sac - Thonglor Rooftop Bar currently holds a 4.9 rating across more than 2,400 Google reviews, which is unusually high for a Bangkok rooftop at this altitude.
You arrive via the hotel lift and step out onto an open-air terrace framed by the pool on one side and the Sukhumvit skyline on the other. Seating is a mix of lounge couches, low tables around the water, and bar stools near the cocktail station. From Thursday through Saturday a resident DJ plays 80s pop, hip-hop, funk, and R&B, and the volume climbs as the night goes on. Sunday through Wednesday it runs quieter, better suited to a long drink and conversation. The bar opens at 5:30 PM daily and closes at 12:30 AM on weeknights, 2:00 AM on Fridays and Saturdays. It is also pet-friendly, which is rare for a Bangkok rooftop, so you will often see dogs parked next to their owners at the lounge tables. Service is relaxed, and drinks come with unlimited popcorn alongside the American-style comfort bites on the menu.
The drinks list leans hard into the 80s-inspired cocktail menu, a retro-themed program of nostalgic classics and party drinks that tracks with the graffiti-and-string-lights aesthetic. The house signature is the Earthquake, a cocktail reviewers single out for its bold, theatrical presentation and the one most tables order at least once. Food stays deliberately casual to match the setting: American-style comfort bites designed to share across a lounge table, backed by bottomless popcorn that arrives with every round of drinks. The outdoor cinema screen is the other draw worth timing a visit around, turning the pool deck into a movie night on scheduled evenings.
Cul de Sac - Thonglor Rooftop Bar is on the 10th floor of The Quartier Hotel at 413 Sukhumvit 39, in Watthana. It sits roughly between Phrom Phong BTS (the closer station, about a 10-minute walk down Soi 39) and Thonglor BTS, so either works depending on which side of the neighbourhood you are coming from.
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