Houlder and Monarch Hill Pits is a 0.7-hectare (1.7-acre) geological Site of Special Scientific Interest in Upper Halling in Kent, England.

[1][2] It is a Geological Conservation Review site.

[3] This site has a sequence of deposits covering the end of the Last glacial period, with two sheets of glacial deposits separated by a fossil soil assigned to the late glacial interstadial around 13,000 years ago.

It provides evidence of lithostratigraphic and biostratigraphic changes during this period.

[4] The quarries are private land with no public access.