T38 is higher at 160m and costs ¥740. Sapporo TV Tower is 90.38m and costs ¥1,200, but its position at the end of Odori Park gives the more recognisable view.
The 189-hectare park is designed as one sculpture, and its size decides the visit. Walking works, but a rental bike is what lets you reach the major works.
The seafood market visitors mean is the Curb Market beside the wholesale market. Nijo Market is a separate downtown market, far easier to combine with Odori.
The outdoor grounds open 29 April to 3 November. The greenhouse is closed indefinitely because of ageing, which removes the usual winter visit entirely.
Most of the exhibition floor works without Japanese because it is hands-on. The planetarium does not: every programme is in Japanese, including the live narration.