National or local parks; often conservation authorities and local governments are willing to, and do, rent out or reserve certain parks for those who may want to use the beautiful space for their events. Some of the stipulations to do so may be to respect and be aware of nature and the natural surroundings.
Farms; some orchards and farms offer an excellent setting for rustic events such as weddings and parties. These are often great venues in any season, and some are dedicated entirely to events, others can be rented upon request.
Vineyards; vineyards make a gorgeous and exciting setting for events, especially those who enjoy grapes in their glass.
Cottages; local cottages and cabins often have outdoor space which can be great for things such as family reunions, retreats, camps and parties for nature lovers and informal type events.
Caves and caverns; if this is your thing, many different caves can be rented if it suits the event you are planning or hosting.
Gardens; local botanical gardens or public gardens will be an excellent setting for engagement parties, bridal showers, baby showers and even birthday parties.