Here are several well-known hotels in Colombo that either run their own small-group/guest excursions or have a concierge / travel desk that arranges small-group tours for guests:

• Shangri‑La Colombo — advertises a Colombo city tour/activity offering (hotel-linked city tours/private sightseeing options). (activities.marriott.com)
• Cinnamon Grand Colombo — Cinnamon Hotels runs guided Colombo experiences (Colombo Wetlands, “Spiritual Colombo”, etc.) and lists guest excursions on its site. (cinnamonhotels.com)
• Cinnamon Lakeside Colombo — part of Cinnamon’s Colombo properties with on‑site “experiences” and guided excursions (wetlands, cultural walks) run for guests. (cinnamonhotels.com)
• Galle Face Hotel — has an on‑site concierge/“Expeditions” team, hotel history tours and arranges Colombo excursions for guests. (gallefacehotel.com)
• Taj Samudra, Colombo — offers a travel desk / Golden Keys concierge and is the stop/host for hotel-inclusive city‑tour experiences (e.g., city tour + high tea). (tajhotels.com)
• The Kingsbury Colombo — hotel “Experiences” pages promote guided visits to Colombo highlights and the hotel arranges nearby excursions. (thekingsburyhotel.com)
• Hilton Colombo / Hilton Colombo Residences — property listings show concierge and “tour/ticket assistance” services (hotel concierge commonly arranges small-group tours or partners with local operators). (hotels.com)

Quick tips for booking:

• Ask the hotel’s concierge or travel desk about “small‑group” or “shared” departures (these are often half‑day or full‑day small-group city tours, tuk‑tuk safaris, wetlands birding, or food/street‑food walks). (cinnamonhotels.com)
• Booking directly with the hotel can be easiest for pick‑up/drop‑off and quality control, but compare prices with local tour providers (hotels sometimes add a markup). (expedia-aarp.com)
• Group size, schedule and availability change seasonally — confirm dates & exact group sizes with the hotel before arrival. (activities.marriott.com)

If you’d like, I can:

• check current small‑group tour options and schedules for a specific hotel and date, or
• fetch contact details / direct booking links for any one (or more) of the hotels above.