Copenhagen Botanical Garden is an informal garden with free admission.

Picnicking is a must, as is a stroll through the formal and informal gardens.

The formal and informal gardens are freely open to the public.

The Ismaili Centre is set in a landscaped park, composed of both formal and informal gardens.

The museum grounds contain formal and informal gardens.

A walk or bike ride through Marie Antoinette's informal English garden follows.

The park is steep and is divided into informal gardens, a small nature reserve and open grassland.

It's famous (locally at least but hopefully, nationally as well), as a former 17th century coaching house set in a lovely informal, sheltered garden.

I put this description in quotes because it is an informal garden, discreetly signposted.

The mansion and its extensive formal and informal gardens and grounds are open to the public each summer.