The site in north Northants has been closed since February 2026.
But following some essential conservation work, visitors can now once again explore the unique history, architecture and landscape of Lyveden.
A National Trust spokesman said: “Surveys carried out in 2024 identified significant decay in the lodge’s timber lintels, prompting essential conservation work.
"Specialist teams repaired damaged oak, restored stonework and repointed walls using traditional lime mortar.
"Conservation work was carefully planned to protect resident bat populations.”
The unfinished Elizabethan lodge was built in the late 16th century by Sir Thomas Tresham and is renowned for its rich Catholic symbolism.
It sits within one of England’s oldest surviving gardens, featuring canals, terraces, orchards and viewing mounds.
