Seattle shimmers like an impressionist painting on sunny days at the Hiram M Chittenden Locks. Here, the fresh waters of Lake Washington and Lake Union drop 22ft into saltwater Puget Sound. You can stand inches away and watch the boats rise or sink (depending on direction). Construction of the canal and locks began in 1911; today 100,000 boats pass through them annually. You can view fish-ladder activity through underwater glass panels, stroll through botanical gardens and visit a small museum.

　　Located on the southern side of the locks, the fish ladder was built in 1976 to allow salmon to fight their way to spawning grounds in the Cascade headwaters of the Sammamish River, which feeds Lake Washington. Keep an eye out for the migrating salmon during spawning season (mid-June to September). Nets keep them from over-leaping and stranding themselves on the pavement. Meanwhile, sea lions chase the fish as they attempt to negotiate the ladder. Displays near the fish-ladder windows help you identify the various species.

　　At the northern entrance to the lock area is the Carl English Jr Botanical Gardens, a charming arboretum and specimen garden. Trails wind through beds filled with flowers and mature trees, each labeled. Flanking the gardens is a visitor center containing a small museum documenting the history of the locks.