The owners of Jaakkola Manor are known since 1575. The present main building was built in 1927 with Empire influences, and replaced an earlier main building which was demolished in 1926.

The history of Jakkarila Manor dates back to the beginning of the 17th century, but the owners are known since the beginning of the 16th century. The present main building was built in the Rococo style in the beginning of the 1760s. It has been reconstructed in the 1840s and in the end of the 19th century. The wallpaper has been transfered to the National Museum of Finland.

Jeggars Manor is also known as Lill-Hila manor. It was founded in 1813 when Hila Manor was divided into Stor-Hila and Lill-Hila. The owners of Hila Manor are known since 1540. The main building of Lill-Hila manor was built in 1812-1813. The manor has been renamed to Jeggars manor in the 1890s.

The main building of Jokela Manor was built in the 1880s in the Neo-Renaissance style. It is used for conferences and private parties at present.

Jollas Manor was founded in 1798 when Degero Manor which was founded in the middle of the 17th century was divided into four parts. The present main building of Jollas manor was completed in 1919. The granary and the barn are from the 19th century. The manor is owned by Helsinki city since the 1970s, and the main building is used as a private school nowadays.

The history of Jupperi Manor is known since 1540 when it was a part of Gammelgard village, and the owners are known since 1560. The present main building was built in the 1830s. It was remodeled in the end of the 1920s.

The history of Jufva Manor is known since 1543. The present main building was built in the 18th century. The current neoclassical appearance is from the remodeling in the 1830s. It is believed to be planned by Carl Engel.

The history of Jarppila Manor dates back to the 1480s, and the owners are known since 1570. There was a manor castle from the 1570s in the area, but it was demolished by the end of the 17th century. The present main building was built in the Empire style in the 1830s, but the basement dates from the end of the 17th century. The granary was built in 1781 at the site of the manor castle. The manor is used for private parties at present.