Spanning two continents, most of Istanbul's major tourist draws are located on its Europe side, primarily below the Galata Bridge, where such gems as the Blue Mosque, Sulemaniye Mosque, Hagia Sophia museum, the Cisterns and Topkapi Palace are located.

For centuries the home of Ottoman sultans whose empire was based here from 1453 to 1918, Topkapi Palace dominates a hill overlooking the Sea of Mamara, the Golden Horn and Bosphorus Straits. Topkapi is extraordinary and requires four or more hours to tour completely. Still, it's a good idea to start later in the day to avoid the cruise-ship passengers who arrive en masse early in the mornings.

The sprawling, multibuilding complex is best known for its treasures. Highlights include an enameled emerald and ruby-bedecked dagger, jewel-encrusted bow and arrow quiver, a golden set of teacups, several bejeweled thrones, Indian silk brocade robes and some of the world's most impressive diamonds.

Also not to be missed is the Harem, which requires an extra admission fee and which many tour guides skip. Harem, often misconstrued as a high-class house for prostitutes, actually means the royal family quarters. It housed the sultan's wives, relatives, concubines and children. All lived under the watchful eye of the ruler's mother, including eunuchs who posed no challenge to the sultan's collection of favorite women.

The tour visits a selection of apartments, baths and meeting rooms that are said to number nearly 400. Among the most notable impressions are the amazing Iznik blue and green tiles that seem to line every wall. Other areas worth a visit are Topkapi's massive kitchens, council chambers, tower of justice, the collection of sultans' costumes, and the often-crowded holy relics section that is home to may revered objects, including relics from the Prophet Mohammad.

Not far from the Topkapi Palace entrance is the vast and fascinating Istanbul Archaeology Museum. Particularly famous for its ancient sarcophagus collection, the museum (actually several museums grouped together) is the ultimate trove of Turkish treasures. To do it justice, it should be the prime destination of another day.

Many other must-sees — including the Blue Mosque, Hagia Sophia and Cistern — are near each other and can be experienced during a morning or afternoon sojourn. Nicknamed for its stunning interior blue tiles, the 17th century Sultan Ahmet Camil, or "Blue Mosque," which features six minarets and — most exceptional — six domes, is a masterpiece of Ottoman architecture. The approach from the Hippodrome enables visitors to experience the domes as they reveal themselves one after another.

Since this is a working mosque, there's no admittance during or a half -hour before daily prayers. Before entering shoes must be are removed and stored outside the entry, then reclaimed upon departure.

Across a park is Hagia Sofia, whose history is as extraordinary as its architecture. Now a museum, from its sixth century construction until the Ottoman conquest it was the world's largest Christian basilica. In 1453 Sultan Mehmet the Conqueror ordered its conversion into a massive and awesome mosque. That was its role until the founder of secular Turkey, Mustafa Kemal Ataturk, made it a museum in 1934.

Everything is huge here. Massive calligraphy, awesome Byzantine mosaics (best seen on the second floor) and vast space that never seems filled up. Even though thousands of visitors pour through daily, within the massive open area there is a stunning serenity that seems to negate the presence of so many visitors.

Another extraordinary Byzantine remnant is the underground, multi- marble-columned cistern, designed to store the millions of gallons of water that arrived via Roman aqueducts. While it is definitely dank, it is still fascinating to roam through and refreshingly cool during particularly sultry days.

Other Istanbul highlights include the airy, spacious and elegant 16th century Sulemaniye Mosque. Constructed by Sultan Suleman (also known as "the Magnificent" as he ruled during the peak of Ottoman power), its hilltop position makes it an integral part of Istanbul's Old City skyline.

More intimate and virtually unknown to tourists is the somewhat-hidden Rusten Pasha mosque. Magnificent tile work and a calm atmosphere of timelessness make this well worth discovering. Hotel concierges can help visitors find the way.

Along the busy Galata waterfront is the place to find inexpensive sandwiches made of freshly caught fish and washed down with soda or beer. This area is also quite near the Egyptian Spice Bazaar, which caters much more to locals than tourists. Here, goods targeting local shoppers — including spices, pocketbooks, pillowcases and jewelry, as well as interactions with merchants —are available.

Roaming here should prove to be much more rewarding than browsing in the traditional Grand Bazaar. Though architecturally interesting, the Grand Bazaar features a plethora of rugs and other goods produced for, and almost exclusively hawked toward, tourists.

Visitors will also want to get out on the water and visit Istanbul's Asian side. Ferries crisscross the Bosphorus, making short "intercontinental" trips to Uskadar, where there are plenty of less-expensive eating options. It is also possible to sail up the Bosphorus to the entry to the Black Sea or down to the Princess Islands, one of which is car-free and maintained to appear as though it were still the 19th century.

Back in Istanbul's "Europe," close to the ferry terminal is the elegant and opulent Dolhmabahce Palace, where Ottoman royalty moved from Topkapi starting in 1856. While lines to enter can be long, interiors are truly spectacular and well worth the wait. Home to some of Europe's most amazing crystal chandeliers, it also contains the room where Kemal Ataturk died at 9:05 a.m., Nov. 10, 1938. All palace clocks were stopped at that moment and have never been restarted.

WHEN YOU GO

Luxury devotees rank the 324-room Ciragan Palace Kempinski Hotel Istanbul's finest. And Turga, its Turkish specialty restaurant, is one of the city's most elegant and delicious dining options. The location, right on the Bosphorus, is unsurpassed: www.kempinski.com/en/Istanbul.

The Ritz Carlton Hotel, a well-located, 244-room luxury property near Dolhmabahce Palace, is an excellent upscale choice: www.ritzcarlton.com/istanbul.

Topaz Restaurant offers excellent, sophisticated Turkish cuisine that is enhanced by extraordinary Bosphorus views: www.topazistanbul.com.

Kosebaci Restaurant is a traditional kebab restaurant in a relaxed, trendy setting, quite close to major hotels: www.kosebasi.com.

Turkish Airlines offers New York to Istanbul non-stop flights: www.turkishairlines.com.

For general information: www.goturkey.com

Photos courtesy of Barbara Selwitz.