The phrase "a pavilion where" is correct and usable in written English.
It can be used to describe a specific location or setting where an event or activity takes place, often in a formal or descriptive context.
Example: "We gathered at a pavilion where the annual festival was held, surrounded by beautiful gardens."
Alternatives: "a structure that hosts" or "a venue in which".
There is a tot's lot with a pavilion where people can have parties.
There is a good restaurant and a pavilion where visitors can get hamburgers and other less expensive food.
When I got out, I wandered over to a pavilion where numerous bathers were gathered to take their constitutionals.
Cobden, who had owned a sizeable portion of St Peter's Field, earmarked the area for a pavilion where entrepreneurs would gather for political purposes.
There's a pavilion where all manner of climate-related organisations set up stalls and a media room as big as a barn and some gimmicks to provide photographic backdrops – in Paris, somewhat unoriginally – a mini Eiffel tower.
All that is left in what used to be the community of Shiloh is a tree-studded cemetery on a hill overlooking a lake and a pavilion where the one-room Missionary Baptist Church once stood.
A chic young woman and a little girl pedaled their bikes into a private pavilion where a 5-year-old boy was diligently digging a moat in the gravel.
We took a wrong turn to a waterfront pavilion, where a new bride was hugging guests at her reception, and kids wriggled and danced in spite of their dress-up clothes.
And now there is a new garden, opened in January 2001, where I found black olive trees pruned as if they were Japanese maples (which don't grow in the tropics), heard a shishi odoshi ("deer chaser"), whose sound is made by a two-foot bamboo stalk falling on a flat rock, and discovered a Contemplation Pavilion, where a sign urges visitors to "listen with your eyes and see with your ears".
We entered a stone pavilion, where a ceremony was going on.
We met again in a small pavilion where I bought a little wood-block print of a pavilion in the snow, a sight I long to see (and could, since the gardens are open all year).
