Organized by the Amsterdam Canal Museums, Open Garden Days (phone +31 [0] 20 3203660) features 30 canal gardens open to the public, June 17-19, 2011 (10 a.m.-5 p.m. each day). A three-day pass (€15, or $20) provides access to all participating gardens, which can be reached on foot.
Tickets, when available, can be purchased at selected gardens. Advance purchases can be made at the I Amsterdam Ticketshop (Leidseplein 26, terrace side).