Serravles Park is located to the west of the city centre. The Serravles Museum of Contemporary Art is located on the site. Adult admission to the museum and park is 10 Euro. If you only want to visit the park, it costs 5 Euro for an adult entry.
What I didn’t consider was that Lausanne is built on three rather steep hills, connected by bridges, narrow streets, vertigo inducing staircases and, if you are lucky enough to find them, the occasional lift.