Old Idaho Penitentiary

Twilight Tours are happening tonight, Friday, June 5!

We are open for a rare summer evening of guided and self-guided tours - 7:00 pm to 11:00 pm (last admission 10:00 pm).

Admission is only $16 per person, or 2 for $25, for a guided or self-guided experience. Free for Idaho State Historical Society Members!

Visit history.idaho.gov/events for more info or to pre-register. Guided tour times are limited to only 25 people each, first-come, first-served! (Guided tours are at 7:30, 8:00, 8:30, 9:00, 9:30, and 10:00.

Twilight Tours!

Enjoy a summer evening exploring the historic Old Idaho Penitentiary. Twilight Tours are Friday, June 5 and 26, 7:00 pm – 11:00 pm (last admission 10:00 pm).

Admission is $16 per person (or 2 for $25). Register online at https://history.idaho.gov/event/twilight2026/.

Idaho State Historical Society Members receive free admission to Twilight Tours! Not a Member? Learn more and become a Member at the https://history.idaho.gov/membership/.

This event is recommended to guests 13 and older due to mature content and site safety precautions. Self-Guided admission is available, along with Guided Tours every half hour between 7:30 and 10:00. Purchase 7:00 pm tickets for Self-Guided admission, or buy admission at the door.

Doors open for Self-Guided Tours at 7:00 pm (guests can arrive any time between 7:00 pm and 10:00 pm last admission).

7:30, 8:00, 8:30, 9:00, 9:30 and 10:00 Guided Tours (limited to only 25 participants each, first come, first served). Tickets for Guided Tours at the door may be limited.

Note: Please print or save your receipt confirmation for use as your event admission ticket. Old Idaho Penitentiary event tickets are nonrefundable and non-transferable.

This Memorial Day, we honor the lives of Veterans who served and sacrificed in the name of freedom.

On your next visit to the site, be sure to visit the J. Curtis Earl Memorial Exhibit. a world class collection and exhibit featuring historic weaponry and military artifacts dating from the Bronze Age to the Vietnam War era, along with stories of Idaho Veterans.

The Old Idaho Penitentiary is open today (Memorial Day) as our daily summer operating hours begin, 10:00 am to 5:00 pm (last admission 4:00 pm).

J. Curtis Earl Memorial Exhibit at the Old Idaho Penitentiary Learn more about the collection of arms and armaments housed within the J. Curtis Earl Memorial exhibit at the Old Idaho Penitentiary.

Dennis Doppelganger Contest: The Results!

It was a tough competition, but the very handsome Binx won out in the "likes" department this time. We definitely get it - although we have to say, we liked all of the competitors!

Binx's human will be receiving admission to Dennis the Cat Day, plus a Dennis prize pack from the Souvenir Confinement store at the Old Idaho Penitentiary.

Don't forget to swing by and join us for our annual Dennis the Cat Day event tomorrow (Saturday, May 23), between 12:00 pm and 5:00 pm (last admission 4:00 pm).

Enjoy the party with:
- Food and drink vendors!
- Specialty food and pet product merchants.
- Brand new Dennis the Cat merch.
- Prison Pets history presentations (with your donation of pet food, benefiting Simply Cats and the Idaho Humane Society!)
- Scavenger Hunt, games, temporary tattoos, and more activities.
- Music, birthday cake, and more surprises.
- Access to Old Idaho Penitentiary exhibits and historic cell houses.
- Plus the chance to buy the new full-color picture book, "Dennis the Cat Was Here," with illustrators Susan Lasater and Veiko Valencia, and live readings at 1:15 and 2:15!

Register at the door, or get more info and pre-register at https://history.idaho.gov/event/dennis2026/

We hope to see you there!

Thank you to Boise Weekly for sitting down with us to discuss Dennis the Cat Day and the story of Dennis! Check out the article, and be sure to join us for the event this Saturday, May 23!

Register and get more information at: https://history.idaho.gov/events/

Dennis the Cat Day celebrate's felin's impact at Old Idaho Penitentiary Old Idaho Penitentiary's famed and fabled Dennis the Cat will be celebrated Memorial Day weekend. Dennis the Cat lived to be 16 years old and brought comfort to many inmates.

Dennis the Cat Day's food and vendor lineup is worth howling for! Check out everyone who will be at the party this Saturday:

Food from Big Beantz Taco Co. and Pizza Piou, beverages from For the Love of Lemons (https://www.facebook.com/profile.php?id=100091662961516) and Wild Frontier Beer Project (https://www.instagram.com/wildfrontierbeerproject/?hl=en), snacks for humans from City Peanut Shop, and snacks for four-legged friends from Molly's Healthy Pet Food Market.

Donations benefit Simply Cats and the Idaho Humane Society!

Check out more event info on Saturday's Dennis the Cat Day event at https://history.idaho.gov/event/dennis2026/.

In honor of Dennis the Cat Day, coming up this Saturday (May 23), the Old Idaho Penitentiary staff shared their favorite photos of their furry companions:

Sol (Charlee)
Ember and Sage (Charlee)
BaBoi and Gryffindor (Leslie)
Jaxon (Leslie)
Lily (Bryn)
Ruby (Bryn)
T**i (Alexandra)
Roar (aka Rorschach) (Eric)
Pig (Eric)
Moose (Mariah)
Lalita (Mariah)
Pickle (Anthony)
Olive (Anthony)
Niles (Anthony)
Dillon (Jacey)
Missy (Jacey)
Roo (Jacey)
Mr. Tiggs (Kendra)
Harvey (Kendra)
Nellie Bly (Samuel)
Beowulf (Samuel)
Mercy Brown (Samuel)

The Old Idaho Penitentiary is proud to be a Blue Star Museum!

Through Labor Day, active-duty military personnel and up to five family members qualify for free regular admission to the site.

Thank you from the Old Idaho Penitentiary to all of our military personnel for your service.