The question I get asked the most
At the end of almost every tour, someone asks me what to do with their extra day. If they've got wheels, I usually send them to Rovinj or up to Motovun. If they don't, and they're willing to deal with one ferry, I tell them about Brijuni.
I don't guide Brijuni myself. My tours are Pula, walking, Roman stuff, the amphitheater, that whole story. Brijuni is a different operation entirely, run by the national park itself, and that's actually part of why I like sending people there. It's not me selling you another tour. It's a genuinely separate place with its own strange history, and I think it earns a day.
What's actually there
Brijuni (you'll also see it written as Brioni, the old Italian name, and locals use both) is a small archipelago just off the coast near Fažana, a fishing town about 15-20 minutes from Pula. The main island, Veli Brijun, is the one everyone visits, and it's basically one big national park.
Tito used it as his summer residence for decades, and that's the part most people have heard of before they arrive. He hosted heads of state, actors, and various Cold War-era dignitaries there, and some of those visits came with gifts: animals. That's why there's a small safari park on the island today with zebras, llamas, and other species that have nothing to do with the Adriatic climate, descendants of diplomatic presents from places like India and various African states. It's a strange thing to see wandering around a Croatian island and it sticks with people.
There's also a lot of actual ancient history underneath the Tito-era layer. Roman villa ruins on the coast, parts of it visible, parts still being worked on. And if that's not enough eras for one island, there are preserved dinosaur footprints too, from millions of years before any of the rest of it. It's an odd mix and that's honestly the appeal.
How to get there
You don't drive onto Brijuni yourself, and you can't just show up and wander freely either. You get to Fažana first, by bus or a short taxi ride from Pula, and from there you take a boat over to the island, usually as part of an organized visit that includes some kind of guided tour once you're there, sometimes on foot, sometimes on the little electric train they use to move people around the main sights.
I'm not going to give you exact boat times or ticket prices here because they change season to season and I'd rather you have correct information than something I half-remembered. Check the official Brijuni National Park site before you go, or just ask at the ticket office in Fažana when you arrive. Get there with some buffer, especially in July and August when it's busy and boats can fill up.
Who it's actually worth it for
If you've got a full extra day and you like the combination of nature, oddball history, and a slower pace than walking a city, go. It's genuinely one of the more unusual places on this coast and you won't see anything like the safari park elsewhere in Croatia.
If you're someone who hates being on a schedule, who wants to wander off and sit somewhere for two hours without a guide herding you along, know going in that Brijuni is more structured than that. It's not a place you freely roam at your own pace, at least not the main tourable areas. That bothers some travelers and it's worth knowing before you commit a whole day to it.
And if you've only got one extra day and you're trying to choose between Brijuni and something like Rovinj, honestly ask yourself what you actually want. Rovinj gives you an afternoon in a beautiful old town with good food and a relaxed walk. Brijuni gives you a half-day boat trip and guided visit with a weirder, more specific story. Neither is the wrong answer. I just think not enough people know Brijuni exists as an option, so I mention it.
The practical bit
Bring water, sun protection, comfortable shoes even if part of it is the little train, and don't expect restaurants and shops at every corner, it's a national park, not a town. Double-check the boat schedule and ticket prices before heading to Fažana so you're not standing at the dock working it out on the spot. That's really it. It's a good day, just go in knowing what kind of day it is.