Unlike some simmers and unlike Sims Community page I guess there are 3 continents at TS4 world: Europe Windemburg Forgotten Hollow Asia San Myshuno Mt. Komorebi Americas all other worlds...
While trying to figure out what parties I can hold at a Center Park venue type, I stumbled across this webpage about Myshuno Meadows. https://sims.fandom.com/wiki/Myshuno_Meadows Apparently there are historical plaques there? I never found those in game but here are the descriptions. I put this info in a spoiler in case other people want to discover these easter eggs for themselves.
Myshuno Meadows History "This Park was once the estate of scientist and herring baron Barnabas Skye. After his mansion was gutted by fire, the fish mogul gifted his extensive gardens to the people on the proviso that his personal Observatory remain standing and free of use to any budding astronomer living in the city. To this day the telescope is maintained and updated by the Barnabassian Scientific Society."
Llama Freedom Movement "On this spot the Llama Freedom Movement was born. A simple protest, known as the Llamoid Sit-In, shocked the public with its extreme use of acoustic guitars, hair flowers and slightly tuneless singing. Though many years have passed since that day, the spirit of activism remains alive and well, and will continue until all Llamas are free to strut and spit and neck wrestle to their heart’s content. (Plaque paid for by the Llamean Popular People’s Front)"
Disaster Memorial "This plaque commemorates the Shirt Factory Meteor Strike And Subsequent Big Lizard Incident that razed the Fashion District to ash. Like a phoenix reborn, the District has risen from this disaster to become an exemplar of regeneration, with award winning modern architecture and a vibrant festival scene."
Herring Monument "This Plaque was erected to mark 150 years of fishery in our fine city. From the humble kedgeree peddlers of the gold rush era to the mighty height of the Canning Industry, the noble Spangled Herring (Clupea Pallasii Fabulousa) has been the slippery, silvery key to the fortunes of this city. As we step into a bold new century, let us not forget the bounty of the sea, nor the piscine origins of our metropolis."
DynaSign Co. Plaque "Raised in memory of the Open Street Act, legislation which allowed communities of all cultures to organize celebrations in the streets. The progressive vision of our founding fathers has allowed generations of residents enjoy the many delights that ‘Festival City’ has to offer. (Plaque donated by DynaSign Co. ‘If it’s in the streets, it’s on our Signs’ (TM))"
Monument to 'Emperor' Horton "This monument marks the spot where noted eccentric ‘Emperor’ Horton experienced the cities’ first Death by Pufferfish. (Plaque donated by Stove Makers Against Sushi Association)"