There are always plenty of good reasons to visit Europe, but this summer offers four special lures for art lovers: the Venice Biennale; Switzerland’s Art 38 Basel; Documenta, which takes place every five years in Kassel, Germany, and the once-adecade Münster Sculpture Projects.

The Venice Biennale is the oldest, largest, and longest event of the four, opening Sunday and running to November 21. As its name indicates, it takes place every other year; this is its 52nd apparition. It was suspended only during the two World Wars.

A new director is appointed for every Biennale, and this year it is the dean of the Yale School of Art, Robert Storr. The first American to direct the fair, he chose the theme “Think With the Senses — Feel With the Mind: Art in the Present Tense.” It is expected to draw almost 1 million visitors during its five-month span.

The Basel fair, running between June 13 and 17, has been an annual event for the past 37 years, a huge bazaar for sellers and buyers of modern and contemporary art. It is held in two modern buildings at the Swiss Exhibition Center. This year, 300 galleries from 30 countries will participate, showing more than 2,000 artists. At least 55,000 visitors are expected, including dealers, curators, and collectors.

Documenta, a showcase for the avant-garde, began in 1955 as an adjunct to a federal horticultural show. Since 1972, it has been held every five years; this is its 12th edition. It is crammed into four buildings, filled to overflowing. This year, the organizers are expanding the show by throwing a big party on June 15 in the city’s Bergpark Wilhelmshohe, for all the townsfolk. Documenta opens June 16 and runs through September 23, along with a show of midcentury work by American pop artist Jasper Johns.

The Münster Sculpture Projects, which opens June 16 in Germany and runs through September 30, will feature 35 international artists who have created new works for public places. The Münster show began in 1977, so this is only its fourth appearance. Half a million visitors are expected between Münster and Kassel, and there is easy transportation to and from both cities by trains that run every two hours.

Unlike Basel, Documenta, the Biennale, and Muenster are not art markets. They are noncommercial showcases for painting, sculpture, installations, performance art, and video. In Venice, there are scores of national pavilions in the sprawling Giardini garden, more off-beat and experimental work at the Arsenale, and dozens of individual exhibitions running all summer long at different venues around town. At the Peggy Guggenheim Foundation, for example, Joseph Beuys and Matthew Barney are presenting an installation called “All in the Present Must Be Transformed.”

It’s only once every 10 years that all four events occur together. Organizers are promoting the idea of a Grand Tour, encouraging visitors to hop to each city.

If I were writing a Baedeker for the events, I’d recommend starting at Basel, simply because the show is so short, and so frantic, that you don’t want to risk missing it. Then I’d go on to Documenta and Münster for a few days, and wind up (or wind down) in Venice.

Venice is especially dear to my heart. I remember the outrage and disappointment of 1968, when, in the wake of student riots in many European countries, organizers decided not to award a top prize, as a gesture of democratic “equality.” (This decision was rescinded several years later.) I remember the pavilion of the Soviet Union, quite austere and never ready on time for the opening. I remember an Israeli installation — a huge greenhouse with cucumber plants growing inside all summer long — and a Brazilian pavilion that buzzed fearsomely with real beehives.

The program this year is sure to have some surprises: It always does. More than 70 countries are participating, from Afghanistan to Venezuela. Women are making a strong showing. They are the featured artists in several national pavilions: Susan Norrie (Australia), Tracey Emin (Great Britain), Sophie Calle (France), Isa Genzken (Germany), and Jill Mercedes (Luxembourg). The artist representing America is Felix Gonzalez-Torres, a Cubanborn conceptual artist who died in 1996 at the age of 39. It is only the second time an artist has been chosen posthumously for the American pavilion; the other one was Robert Smithson in 1982.

Several nations, or groups of nations, are building their shows around a political or philosophical statement, such as “Globalization … Please Slow Down” (Thailand), “Is There a Future for Our Past?” (Japan), “Culture and Leisure” (Hungary), “Citizens and Subjects” (the Netherlands), “Low-Budget Monuments” (Romania), and “Welfare — Fare Well” (Finland, Norway, Sweden).

Although the Biennale focuses on new talent, there will be many exhibitions around Venice in various museums and galleries featuring established artists, and a surprising number of prominent Americans among them: the late Sol LeWitt, Louise Bourgeois, Bruce Nauman, Jenny Holzer, Ellsworth Kelly, Robert Ryman, Bill Viola, and Nancy Spero.