The former municipality covered an area of 6.62 km² (of which 0.23 km² water) and had a population of 14,906 in 2005. Since January 1, 2006, it is part of the Teylingen municipality.
The name Sassenheim consists of two parts; the first (Sassen) means Saxons, and the second portion (heim) is Old Frankish for "home".
Sassenheim was formed between the towns of Leiden and Lisse on the eastern edge of the old coastal dunes where the main road from Leiden to Haarlem was located. Along this road many castles and estates were built, including the mansions along Sassenheim's Main Street (Hoofdstraat) dating from the early 1900s. The village church is built on a dune top and portrays a variety of construction styles. Sassenheim is located in an area called the "Dune and Bulb Region" (Duin- en Bollenstreek). Historically, Sassenheim had a large bulbflower industry but this has now all but disappeared, only a few fields remain.
The ruins of Castle Teylingen
One of the most interesting attractions in Sassenheim are the ruins of Castle Teylingen. This stronghold was built to guard the north-south route in Holland and later became a residence. Its outer walls date from the beginning of the 13th century. Around 1570 during the Eighty Years' War, the castle was heavily damaged but rebuilt afterwards. It was bought by the State in 1889 and restored in 1900.
