It's easy to fall in love with a cold climate in Irkutsk, Siberia

IRKUTSK is more than a junction on the Trans-Siberian Railway: It is a city guaranteed to change your mind about Siberia. One should travel here by train to appreciate Irkutsk's vast separation from European Moscow. But if you don't have 3 1/2 days to spare, there is a six-hour flight from Moscow, a flight that whisks you across five time zones to this outpost of Russian culture a stone's throw from the Mongolian border.

I came in February to experience the rigors of Siberian winter, but found Irkutsk sparkling in sunshine, with temperatures in the 20s (F.). One mild evening brought out joggers and baby carriages on the boulevard along the Angara, a fast-flowing river that is the only outlet for Lake Baikal's waters. Fishermen crowded the river's icebound banks as the sun set.

My image of urban Siberia had consisted of rough mining towns, rows of hastily thrown up apartment blocks among the sunless wastes. Irkutsk has its souless apartments and belching smokestacks, but these in no way define its character. Described as the ``Paris of Siberia'' by Chekhov, it has not lost its charm. The grand constructions of merchants who prospered in the last century on gold and trade with the Far East, are matched in beauty by some of the wooden houses just a few blocks from the river front Intourist Hotel. With their lacy carvings and brightly painted shutters, they provide a glimpse of the old Russia that has all but vanished from the larger cities.

Locals will point out some of the curiosities of Irkutsk architecture, like the wooden houses with modest one-story fa,cades that face the street to fool the taxman and bloom into two-story dwellings complete with balconies at the back.

Russian explorers founded Irkutsk as a trading outpost in the 17th century at the spot where the Irkut River flows into the Angara. It soon became Russia's window on the East, where missionaries came to study Mongolian and (in the 1750s) a school opened to teach navigation and Japanese. It remains an important regional capital, the center of the fur trade and the gold mining industry, as well as the gateway to nearby Lake Baikal.

In the 19th century two waves of exceptional exiles ennobled Irkutsk. The failure of the 1825 Decembrist uprising caused some of the cream of Moscow and Leningrad society to be exiled here. A handful of wives and fianc'ees followed and later established elegant homes when the rebels were freed from labor in the mines and allowed to live in Irkutsk. The radical chic of Princess Maria Volkhonsky's salon drew many artists here. Her piano and other Decembrist artifacts can now be seen in the Volkhonsky house museum.

The wooden mansion is being made the centerpiece of a Decembrist museum complex. Along with the nearby Trubetskoy house, it serves as a reminder of Russia's struggle against tyranny. Decembrist wives' heroism is still keenly felt: at the Znamensky Monastery there were four red carnations on Ekaterina Trubetskoy's grave.

By 1885, exiles formed one-third of the Irkutsk population. After the Polish uprising of 1863, a group of well-educated Poles arrived. They shared their knowledge of science, languages, and the arts with the local population. They also left behind a handsome brick Roman Catholic church on the city's main square. Today it serves as a concert hall, with its East German organ as the main attraction.

The face of this main square, now named after the Bolsheviksergei Kirov, has changed many times since the city's birth. As the site on which Irkutsk was founded, the square once had a variety of wooden buildings; these were either destroyed by fire or torn down.

One early stone building remains - the Church of the Savior, constructed in 1706. A large white-painted structure with belfry added in 1758, it possesses an austere grandeur entirely appropriate to Siberia. Restored in 1981, it is now a branch of the Irkutsk Museum of Regional Studies. Across the square stands the slightly younger Church of the Apparition our Lord. It is being used as part of the fine arts museum.

Foreign visitors inevitably are lodged at the Intourist Hotel, which is clean and inexpensive, but Spartan. Narrow beds, small rooms, and thin walls provide the ambiance of a university dormitory. But the Intourist staff are efficient and friendly.