Cob is a natural building material made from a mixture of clay, sand, straw, and water. It is known for its excellent thermal mass, which helps regulate indoor temperatures, making it energy-efficient. Cob structures are often sculptural and can be shaped into various forms, allowing for creative architectural designs. Historically, cob has been used for thousands of years in various cultures, particularly in regions like England and Morocco. Buildings made from cob are durable and can last for generations if properly maintained. Today, cob is gaining popularity in sustainable building practices due to its eco-friendly properties and low environmental impact.