Villa Durazzo Park is an enchanting park to visit. I'd recommend visiting it after seeing Portofino, if you have time left in Santa Margherita before taking your train. This villa dates back to the 17th century, and it was built as a noble residence. Unfortunately, I didn't have much time, so I couldn't go inside. The entrance fee is €5 for the villa, instead the park is free to visit.
The gardens offer spectacular panoramic views over the Ligurian coastline. They are adorned with lush vegetation, exotic plants, statues, fountains and colourful flowers. I really liked it and wish I had more time to visit without rushing.