Here are urban (or near‑urban) retreats in Singapore that offer structured wellness programmes, day‑retreats or multi‑day packages — short summaries, what they offer, and practical notes for booking.

1. COMO Shambhala (COMO Orchard / COMO Shambhala Singapore)

• What: COMO’s large urban flagship in Orchard offers a full wellness centre with classes (yoga, pranayama, HIIT), private coaching (fitness, mobility), recovery tech (red‑light therapy, contrast therapy rooms, mild hyperbaric oxygen), and a healthy COMO Shambhala Kitchen. It’s designed for city‑dwellers who want a compact but comprehensive retreat experience.
• Good for: bespoke short retreats, daily wellness classes, sports‑recovery and physiotherapy.
• Practical: book classes and specialist sessions in advance; programmes and equipment are in‑house. (leisureopportunities.co.uk)

2. Six Senses Duxton (Six Senses Singapore)

• What: a wellness‑focused city hotel in Duxton/Hill Street that integrates traditional Chinese medicine (resident TCM physician), wellness screenings, acupuncture, qigong, dietary therapy and tailored short wellness programmes. They run multi‑day and one‑day offerings that include consultations, movement, and spa therapies.
• Good for: guests wanting integrative, TCM‑led urban wellness experiences within the CBD.
• Practical: check availability for medical/wellness consultations; programmes often require prior booking. (ttgasia.com)

3. Banyan Tree / Mandai Rainforest Resort (Banyan Tree Spa — Mandai)

• What: although located at Mandai (adjacent to nature reserves), Banyan Tree’s Mandai property runs wellbeing sanctuaries and retreat‑style programmes (daily gentle yoga/Pilates, sound baths, workshops such as DIY body scrubs, essential oil blending, herbal oil workshops) plus signature Banyan Tree spa therapies and multi‑night Wellbeing Sanctuary Stay packages.
• Good for: nature‑adjacent retreats without leaving Singapore — spa workshops, restorative programmes and multi‑night packages.
• Practical: many activities are run on a weekly schedule; contact concierge/spa for the activity guide and bookings. (banyantree.com)

4. Auriga Spa — Capella Singapore (Sentosa)

• What: Capella’s Auriga Spa is a high‑end, holistic spa (Forbes five‑star) offering signature Intuitive Wellness massages, detox and day‑retreat packages (detox day, digital‑detox retreats, meditation + massage day‑programmes), and spa facilities (vitality pool, herbal steam, hot/cold experiences).
• Good for: day retreats, couple or solo restorative programmes and spa‑led detox days with access to resort facilities.
• Practical: popular for day‑retreat packages and themed weekend retreats — reserve early, especially on weekends. (straitstimes.com)

5. The Fullerton Spa (The Fullerton Hotel Singapore)

• What: city‑centre spa offering curated wellness packages, signature Asian Heritage treatments and short “spa‑retreat” day packages (massage + foot/acupressure + scrub), plus regular public classes such as “Yoga by the Bay” (outdoor yoga by Marina Bay).
• Good for: quick urban spa retreats and wellness add‑ons for business travellers or shoppers in the Marina Bay / Civic District.
• Practical: good option for single‑day wellness escapes; bookings via hotel spa website. (straitstimes.com)

Quick comparison and booking tips

• Programme length: COMO Shambhala and Six Senses offer more structured multi‑day or medically informed programmes; Auriga (Capella) and Banyan Tree are excellent for 1–3 day detox/retreat packages and immersive spa workshops; Fullerton and hotel spas suit half‑day to full‑day urban wellness escapes. (leisureopportunities.co.uk)
• Typical price ranges (approximate): single treatments S$150–S$480+; day packages S$200–S$600+; multi‑day curated wellness stays vary widely (from a few hundred to several thousand SGD depending on inclusions). Always check each property for current pricing and offers. (straitstimes.com)
• How to book: book directly on the hotel or spa website (or by phone/email) to view current retreat schedules, join waitlists, and confirm any medical/wellness consultation requirements. Many urban programmes have limited slots and run on set dates — reserve in advance. (leisureopportunities.co.uk)

If you’d like, I can:

• Find current retreat dates, exact package prices and availability for any one of these properties (I’ll check live schedules and give direct booking pages and earliest openings).
• Or narrow options by neighbourhood (Orchard, Marina Bay, Sentosa, Duxton) or by type (spa day, medical/TMC‑led, fitness‑focused, multi‑day detox).