Paying museum and attraction admission fees in cities you are visiting can add up. That’s why multi-passes offered by city tourist bureaus and travel websites are attractive.

But as I explain in this recent story for CNBC.com, depending on the city and your touring pace, buying a pass may not always be the right choice:

Marketed as a convenient way for tourists to save money on entrance fees, passes often include appealing extras like local transit passes, priority entrance lines and the option to make return visits to the most popular and scenic sites.

Still, travelers need to do their homework to determine if the deals really offer good value, basing the decision on how long they’ll be in town and what they plan to do while there,” said Arabella Bowen, editor-in-chief of Fodor’s Travel. Otherwise, “you could wind up spending more than you need to.”

For visitors to Italy, for example, Bowen recommends the 48 hour Roma Pass. That option includes unlimited use of buses, trams, metro, free admission to two museums or archaeological sites of your choice, plus discounted entrance to others, all for 28 euros, or about $31.

Separately, admission to the Colosseum/Palatino/Roman Forum and the Capitolini Museum adds up to 27,50 euros, “so visiting two attractions alone pays for the pass,” said Bowen, “At that price, you might as well buy it for the additional benefits of public transit and other discounts — they’re essentially free.”

Lonely Planet’s Alex Howard, destination editor for Western USA and Canada, likes Vancouver’s 160-page City Passport. It sells for 25 Canadian dollars (about $18) and offers over $1,000 in potential savings so pays for itself after only a handful of coupons.

Howard, however, said Las Vegas travelers who use the city’s travel pass should beware.

“Several of the advertised attractions are off the Strip, requiring visitors to hop in a car,” he said, which means more out of pocket costs. “Plus, the High Roller, the Neon Museum and the Mob Museum, three of my personal favorite Vegas attractions, are conspicuously absent.”

Don’t ignore those ‘hidden gems’

Museums and attraction passes come in a wide variety of flavors. That means users have to work a bit harder to search for the ones with the most value — and might want to pay closer attention to those ubiquitous coupon books in hotels and airports they frequently ignore.

“Some coupon books are put together by chambers of commerce and are passed out to visitors and inserted into glove boxes in car rentals,” said Scott McMurren, who curates the Alaska Toursaver guide filled with 2-for-1 offers.

Many tourism bureaus craft and sell their own attractions passes, while others work with one or more outside company that specializes in creating bundled passes. In some cases, the coordination between tourist agencies and businesses helps subsidize the cost of the passes for travelers.

For example, Choose Chicago has teamed up with organizations like CityPASS and Go Chicago Card to promote their offerings rather than compete against them, said Melissa Cherry, senior vice president of marketing and cultural tourism for Choose Chicago.

Salt Lake City, on the other hand, has been promoting and selling its own Visit Salt Lake Connect Pass for about 15 years. In Salt Lake, each attraction pays a nominal annual fee to help with operational costs of the program, and receives a reimbursement of approximately 70-80 percent of the ticket window rate on each redemption.

“We looked at Salt Lake and the surrounding area’s most popular attractions, making sure the ones we selected met certain parameters, such as being open year-round and at least six days per week and receiving minimum of 100,000 visitors per year,” said Shawn Stinson, a spokesman for Visit Salt Lake.

“Any profit goes toward operational costs, and from there any remaining funds goes back into the promotion of the pass,” said Stinson.

The Leisure Pass Group, which offers city passes for London, Paris, Berlin and Dublin, includes a good mix of ‘big hitters’ and ‘hidden gems,’ said Amanda Truman, the company’s product marketing director.

In addition to exposure they might not get on their own, attractions automatically get a payment each time a visitor uses a pass for entry. “And the fact that our customers have not physically spent cash to gain entry also often leads to an increased ‘secondary spend’ in the gift shop or cafe,” said Truman.

Launched in 1997, CityPASS offers bundled passes for 12 destinations, including Boston, San Francisco, Philadelphia and New York City. Attractions don’t pay be to part of the program but do make money on the sale of the CityPASS ticket booklets, and only a limited number of high-draw attractions are included in the pass for each city.

“If you put too many attractions on a pass, visitors feel pressured to race from place to place to maximize the value,” said CityPASS spokeswoman Deborah Wakefield. “Our owners feel that if you limit the number of attractions, visitors can enjoy the attractions at a leisurely pace and still have time to do other things in the city, such as explore neighborhoods, go shopping, take in a Broadway show, et cetera.”

Wakefield said while not everyone uses all the tickets in their CityPASS, most realize “a healthy discount on the admissions.” She urges travelers to study all available passes to make sure they pick a pass that includes the attractions they most want to see.

Go City Cards, currently offered by Smart Destinations in 11 cities, are available in several multi-attraction configurations, including a build-your-own product that lets visitors purchase discounted admissions to only those attractions they’re sure they want to visit.

Those choosing all-inclusive pass options, which tend to be more expensive, should “make sure to make the most of it,” said John Walsh, chief marketing officer for Smart Destinations. “So get up early and carefully plan out your day.”