Stroll the forecourt for iconic photo opportunities and a short guided exterior look at the Opera House; tours run most days (check hours) if you want inside access.
Breakfast overlooking the famous ocean pool and waves — great way to start the Bondi to Coogee walk; check seasonal opening times (often early morning).
Lovely harbour-side gardens for a relaxed wander and views across to the Opera House; gardens are open daily but close/change hours seasonally so check before you go.
Take the scenic ferry from Circular Quay to Manly for sea views and a different beach vibe — ferries run from early morning to late evening (timetables vary).
Most ordinary restaurants are closed on 25 Dec — book a hotel Christmas lunch (e.g. The Langham or similar) or a special harbour cruise well in advance.
Depart early for a full-day sail to Whitehaven Beach and Hill Inlet with snorkel stops on a reputable operator; most trips run ~7:00am–5:00pm so check exact times when booking.
Relax by the lagoon or book a short activity (lagoon swim, local gallery or short reef intro trip); keep the afternoon light to rest for the evening celebrations.
Guided tours typically depart early (7–8am) and include rainforest walks, crocodile-spotting boat cruises and Cape Tribulation beaches; tours return in the early evening.
Most reef operators depart early (7:00–8:00am) and return mid-to-late afternoon; trips include snorkel gear and lunch, with optional introductory dives available — verify operator safety & departure times.
Take a focused afternoon trip to Katoomba to see the Three Sisters and Scenic World attractions — Scenic World often open ~9am–5pm but hours differ seasonally so check before booking.