The series of buildings nestled on Alyson Hannigan's Encino, California property have floor-to-ceiling windows that flood every room with sunlight -- the opposite of what you'd picture for a witch casting monster-slaying spells.

But the dark wood, geometric architecture and solid wood-and-concrete structures give the compound at 4411 Noeline Avenue that little bit of an edge.

Hannigan, who starred as Willow in "Buffy the Vampire Slayer" and as Lily Aldrin in "How I Met Your Mother," has put her home on the market, with an asking price of $18 million.

The 5-bedroom, 8-bathroom, 142,291-square-foot property -- designed by noted architect Peter Tolkin -- sits on 3.26 acres just south of Ventura Boulevard.

That's according to the listing, co-held by Michael and Alexis LaMontagna of Hilton & Hyland Real Estate, and Jade Mills of Jade Mills Estates.

"The house is made up of a series of board-formed concrete, wood and glass pavilions connected by gallery spaces that together define a central courtyard," that listing reads.

Aside from the courtyard, the grounds include a tennis court, a pool, a guesthouse and a wide range of thriving native plants, including "sycamores, orange, avocado, palm trees and succulents," the listing says.

Inside the 2001 building, cavernous ceilings and exposed wood and metal beams pair with open layout living, kitchen and dining rooms -- all of which have views of the natural beauty outside.

Scroll to see more photos of Alyson Hannigan's 2001 Encino home: