CAPE ELIZABETH —  A group leading the effort to create an arboretum at Fort Williams Park is holding two informational site walks.

The first walk organized by the Fort Williams Steering Committee will take place next Wednesday at 6:15 p.m. and the second will be on May 16 at 2 p.m. The walks will begin at the picnic shelter on the bluff overlooking Portland Head Light. The walks are free.

The walks aim to educate about invasive plants in the park and the role of the proposed arboretum project. Richard Churchill, a horticulturist and arborist, will lead the walks.

The concept calls for 15 planting sites, including a demonstration site, around the park on existing walkways. Work on the demonstration site is expected to begin this year.

The committee is now beginning a fundraising campaign for the demonstration site. The one-acre area at the northern end of the cliff walk is expected to cost about $350,000.