Labatt Memorial Park is a baseball stadium in London, Ontario. Opened in 1877, it is now recognized by Guinness World Records as the oldest baseball field diamond in the world.

The origins of Labatt Memorial Park date back to 1868 and the founding of the London Tecumsehs Baseball Club in London, Ontario. The Tecumsehs initially played their games at the local military grounds or the old fairgrounds, but in 1877 moved to the newly built Tecumseh Park on the banks of the River Thames (In case you’re wondering, back in the late 1790s, the British general and first Lieutenant Governor of Upper Canada, John Graves Simcoe, was obsessed with renaming towns and rivers after things back in England.).

The Tecumsehs played their first game at Tecumseh Park on May 4, 1877, and in so doing created a piece of record-breaking baseball history. The diamond, renamed the Labatt Memorial Park in 1936, is now recognized as the oldest continually operating baseball ground in the world.

Such recognition, however, wasn’t so easy to obtain. In 2007, the Guinness Book of World Records first published the record for the world’s oldest baseball field, but it wasn’t Labatt Memorial Park who made it into the hallowed pages of the famous book.

Instead, and much to the dismay—even anger—of London and indeed Canadian baseball fans, Guinness gave the record to Fuller Field in Clinton, Massachusetts. After the announcement, one prominent London resident, Joe O’Neil, was interviewed by The London Free Press. “People I’ve been talking to in the community are getting wound up about this,” he explained, and made clear their willingness to set the record book straight.

Their case was strong. The history books clearly showed that Fuller Field opened in 1878, a full year after Tecumseh Park/Labatt Memorial Park. Fuller Field, meanwhile, insisted they were justifiably listed by Guinness as the “world’s oldest continually used baseball diamond/ field” due to an arguably pedantic technicality.

The home plate and bases at Fuller Field, they argued, had remained in exactly the same locations since their diamond opened, whereas the home plate at Labatt Park had been moved (within the same field) from its original location in 1877. This was true: the London ballpark did rotate the position of its diamond after a flood in the 1880s.

For the Londoners, however, that was hardly enough cause to disqualify their baseball field from being the world’s oldest. It all now depended, however, on the notoriously finicky folks at Guinness.

In September 2008, a year after recognizing Fuller Field, Guinness published the 2009 Guinness Book of World Records. And there, on page 191, was the entry for “World’s Oldest Baseball Diamond,” now updated to list Labatt Memorial Park as the record holder. To this day, Labatt Memorial Park is still listed on the Guinness website as the “oldest baseball field diamond,” with not a mention of the unfortunate Fuller Field.