SAN JOSE, Costa Rica - Pity the poor Costa Rican postman. Sure, he doesn't have to deal with sleet or snow. But consider what passes for an address here:

From the Tibas cemetery, 200 meters south, 300 meters west, cross the train tracks, white two-story house.

That's actually a pretty easy one. Making his rounds on the outskirts of this capital city one recent morning, carrier Roberto Montero Reyes pulled envelopes from his canvas sack whose addresses read like treasure-hunt clues or lines of haiku.

There was one for someone who lived on "the south side of the Red Cross" and another for a family whose home is "125 meters [410 feet] west of the Pizza Hut."

"You've got to be a mind reader . . . a historian and a detective" to do this job, said Montero, a 27-year veteran, who walks his route in camouflage-print sneakers.

It might be difficult for GPS addicts to comprehend, but Costa Rica doesn't have a standardized system of addresses - at least not ones that can be typed into MapQuest.

Many streets aren't named, and virtually none has a sign. Many houses don't have numbers. Only a few pockets of the country use anything close to the "123 Main St." format that Americans would recognize.

Instead, most Costa Rican addresses are expressed in relation to the closest community landmark. In colonial times, that was the church or town hall. Today, it could be a fast-food joint or car dealership.

For some, the system is a reassuring link to their country's agrarian past, a colorful affirmation of what it means to be "Tico," or Costa Rican.

Almost everyone beams when talking about the "old fig tree" and the "old Coca-Cola plant." Both of those San Jose-area landmarks have been lost to history, but locals still cite them when giving directions. For a disoriented visitor, it's proof that magical realism is alive and well in Latin America.

"It's part of the idiosyncrasy of Costa Ricans," said historian Francisco Maroto Mejia, director of the postal museum for Correos de Costa Rica, the nation's postal service.

The trouble is that these rustic addresses aren't keeping pace with Costa Rica's development. A nation of more than four million, Costa Rica boasts the highest standard of living in Central America, and has a vibrant technology sector. But until recently, it took an average of nine days to deliver a letter - if it got there at all.

Postal authorities say that 1 in 5 pieces of mail is undeliverable because they can't figure out where the addressee lives. The problem is worse in new subdivisions, where neighbors don't know one another and can't advise carriers.

Mail is just one problem. Emergency crews, cab drivers, utility workers and delivery people spend an inordinate amount of time on cell phones and knocking on doors to find out where they are supposed to be.

"It's total chaos," said San Jose-area retiree Claudio Gonzalez, 73, who recently spent three fruitless hours searching for a friend's home in an unfamiliar suburb. "I could find my way easier in a foreign country."

Postal authorities have embarked on a major overhaul. Recent changes in the way mail is sorted have cut the average delivery time to two days nationwide. Now the postal service is assigning numbers, street names and postal codes to every home and building in the country, which measures about 20,000 square miles.

Officials have rolled out more than 430,000 streamlined addresses, mostly in urban areas. They hope to convert the entire country over the next two years if the government allocates about $1 million to finish the job.

Erecting street signs will take a lot longer and cost a bundle. Correos de Costa Rica is trying to persuade the private sector to help pay for that effort.

The biggest challenge will be altering the Tico mind-set, said Alvaro Coghi Gomez, the postmaster general.

"It's a cultural process," Coghi said. "We have to stop thinking about the fig tree."