Queens Gardens is Townsville's most central botanic garden, a green pocket tucked below Castle Hill and close enough to the city centre for an easy walk. It began as an acclimatisation garden in the colonial period, and still has the slightly old-fashioned feel of clipped lawns, tropical plantings, palms, and shaded paths. In a hot city, that shade matters.
This is not a blockbuster sight, but it is a pleasant reset between the Strand, Castle Hill, and the museums closer to the waterfront. Go early or late in the day, when the light is softer and the heat is less punishing. Birdlife, flowering trees, and the quiet residential setting make it a good low-key stop.