Dr. Terry and Heather Dubrow are giving up mansion life for much simpler accommodations ... 'cause they just put their house on the market to fully embrace apartment living.

The reality television couple listed the nearly 9,000-square-foot Beverly Hills home Friday for $25 million. It features five bedrooms and nine bathrooms -- and ya gotta click through the gallery to see the ocean views.

The massive house also boasts a grand entry foyer with two staircases, a huge terrace, and a full-sized tennis court ... perfect for getting a sweat on before jumping into the pool.

The yard also contains a lounge area with outdoor couches ... and also a long table for hosting elaborate outdoor dinner parties.

We spoke with Josh Altman -- who holds the listing with his brother, Matt -- and, he tells TMZ the property is one of the best investment opportunities he's ever seen, giving the new owners plenty of opportunity to customize the pad to their liking or build a beautiful legacy house.

Altman adds, "I don’t know anywhere else you can get 8 prime acres sitting on top of Beverly Hills completely unobstructed anywhere near this price point."

Altman says the only reason the couple's selling is 'cause they've decided to embrace apartment living ... 'cause they don't need a ton of space anymore -- not with only one kid left living at home. JA says they'd rather travel than stay at home.