The privy at Brodsworth Hall, near Doncaster, South Yorkshire, was originally built in the 1860s.
In its heyday, its contents, dubbed "night soil", were emptied daily and spread on the gardens by staff.
English Heritage, which now runs the site, said the privy had been restored to its former glory.
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English Heritage's Kendra Grahame-Clarke said the privy was restored using archival information found at the hall, and is now "one of the poshest outdoor privies in the country".
She said although the facility does not have running water, it features a hole under the seat which can be accessed by a trapdoor allowing "a servant/gardener to collect and spread the night soil at dusk".
The toilet is in its own "secret garden" and also features a pagoda-style roof and pergola trellis.
The original toilet, built by George Ball for three pounds and five shillings, was surrounded by heavily scented blooms, and provided a respite for members of the Thellusson family, who lived at the house.

The 22-year-old was born in Edinburgh but has not been involved in the Scotland set-up before now.
Jones plays for Cape Town-based Stormers in Super Rugby and his preferred position is centre.
He comes into Vern Cotter's 27-man squad after Glasgow Warriors fly-half Finn Russell pulled out after suffering a head injury.
Jones said: "I'm delighted to get this opportunity to play for Scotland. It's a dream come true.
"I didn't go out to South Africa with the intention of becoming a professional rugby player, but, as my career progressed, it become more of a realistic goal to play for Scotland.
"The call came as a bit of a surprise, but I'm thrilled and can't wait to get to Edinburgh next month and play my part in an exciting squad."
The Scotland newcomer was educated in Somerset, but his rugby career took off on a gap-year trip to South Africa in 2012.
He stayed on and helped the University of Cape Town win the Varsity Cup in 2014, scoring in the final, before being called up for Western Province Under-21s.
Jones progressed to the senior team before being called up by the Stormers, for whom he has made 21 appearances.
Scotland play two Tests against Japan on 18 and 25 June, with BBC Scotland providing live television, online and radio coverage.
An outdoor privy is being hailed as "one of the poshest in the country" after being restored at a Victorian country house.
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Scotland have called up South Africa-based back Huw Jones for their June tour of Japan.