Curtain-raiser of a Scottish vacation may be theater. But then there is golf for those so inclined, and lovely parks beckon visitors to Aberdeen

``They say one can walk across London on grass, there are so many parks. Well, we say one can cross Scotland, hole to hole with a golf bag. But when you get to Aberdeen you can rest your clubs and walk among the flowers.'' So said the driver as he taxied us from the railway station. One of the richest cities in Britain, Aberdeen is also one of the most beautiful. Millions of roses - red, pink, yellow, and white - line the streets and fill the parks.

You might expect, with North Sea oil, that this old city on Scotland's northeast coast would have taken on a synthetic veneer, the strut and swagger of a boomtown. But Aberdeen has a long history of affluence from whalers and fishing fleets, shipbuilding and textiles, farming and cattle breeding, and, of course, granite quarrying.

Aberdonians take the recent wealth in stride, insist all oil rigs stand at least 70 miles offshore, and are more apt to boast of their intellectual heritage. And well they might, with the King's College (1495) and Marischal College (1593), Britain's oldest medical school. From the lofty belfry of Aberdeen's Church of St. Nicholas (the Mither Kirk), a 48-bell carillon (the largest one in Britain) peals forth across the old quarter of faculty manses and huge trees shading medieval academic buildings and cloisters.

But a stroll through history must wait. We had come for the theater and had been told that His Majesty's Theatre is the most resplendent in all Britain - second only to London's West End for drama, ballet, and opera.

We took a train from Edinburgh, a two-hour trip along the edge of the North Sea. We crossed the 1-mile railroad bridge spanning the Firth of Forth, then on past coves and tidal basins where dories lay on their sides in the wet gray sand, waiting to be uprighted by the incoming 30-foot tide. Waves breaking against craggy black cliffs sent salty mist up to the famous St. Andrews golf course at Fife. Sheep grazed on the inland side of the tracks, and meadows of electric green rolled gently off toward the horizon.

We passed Dundee - muscular with shipbuilding, spiked with huge cranes, and dirtied with flatcars carrying rusty scrap metal. But the station is calendar art - white-painted pillars with red capitals and yellow rosettes, polished brass doorknobs, window boxes, and manicured flower beds.

The BritRail pass delivered us into the heart of Aberdeen's throbbing modern city just in time to check into our hotel and prepare for an 8 o'clock curtain.

Our Edinburgh friends had not overstated the case. His Majesty's Theater, at the head of Union Terrace Gardens, is the only one in the world built entirely of superb Kemay granite. The domed and columned Public Library, St. Mark's Church, and the theater stand on an imposing block nicknamed ``Education, Salvation, Damnation.''

Inside the theater, we were dazzled by the crystal chandeliers, arched and gilt-trimmed galleries, the Royal Box, and the rich, crimson upholstery and drapery. J.B. Priestley's play ``I Have Been Here Before'' was excellent, but no more of a treat than the sumptuous auditorium itself with its eager audience, mostly young. Tickets were $5 and $8 - with two seats for the price of one on Mondays.

One may come for the theater, but the big surprise of Aberdeen is its splendid array of public gardens with arboretums, fountains, swan lakes, bandstands, and footpaths over filigreed iron bridges.

Schoolchildren in hunter-green blazers, white shirts and ties, tartans and wool knee socks swarmed into Duthie Park for their lunch break. Fairy tale wooden sculpture in the play gardens, model boat sailing, and canoeing make the picnicking ideal.

Heavily wooded Hazelhead Park is a perfect place for jogging, trail riding, or golf. And there are 10 more city parks, some facing seaward.

Seven bus services carry the people of Aberdeen and their holiday guests to the Beach Promenade, sea-edging golf links, and ``bathing stations'' (or bathhouses), and on to bustling modern piers and the ancient fishing community of Footdee.

Visitors should allow strolling time for Footdee -- three enclosed quadrangles of granite cottages with two-foot-thick walls, pretty kitchen gardens, and schooners and flowers etched into the glass panels of their narrow front doors.

Day trips from Aberdeen.

From Jameison's Quay, a person can cruise to the islands of Orkney and Shetland on P&O ferries.

The Northern Belle railway excursion leaves Aberdeen every morning at 11 o'clock and returns at 6:25. Morning coffee, a gourmet lunch, and afternoon tea are served in the diner as the train winds through mountains, over rivers, and past wildlife. A day tour is about $18 inclusive.

Another day's side trip is by car or bus to Royal Deeside, which so enchanted Queen Victoria that she made it the summer residence of the British Royal Family. Balmoral Castle, set in 30,000 acres of mountains and pine forests on the banks of the River Dee, is the setting in September for the most famous of Scotland's Highland Games. When the royal family is not in residence, visitors may tour gardens and exhibitions within the castle.