Nancy Willard's "A Visit to William Blake's Inn" yesterday won the Newbery Medal for "the most distinguished contribution to American literature for children" in 1981, the first book of poems to be so honored in the prize's 60-year history.

"Jumanji," written and illustrated by Chris Van Allsburg, received the Caldecott Medal as "the year's most distinguished American picture book for children."

The winners were announced in Denver by the Association for Library Service to Children. The 4,000-member group, part of the American Library Association, awards the prizes annually "to call attention to and stimulate distinguished writing and illustration in books for children."

"A Visit to William Blake's Inn: Poems for Innocent and Experienced Travelers" (Harcourt, Brace), illustrated by Alice and Martin Provensen, is a collection of nonsense poems inspired by Willard's childhood reading of Blake, incorporating some of the English poet's fantastical creatures.

"Jumanji" (Houghton Mifflin), illustrated with black-and-white drawings, is the story of two children who find a Monopoly-like game about jungle survival, bring it home while their parents are away and discover that the game's events come to life in their living room.

In addition to the medal winners, the ALSC's two 15-member award panels also name a number of "honor books" each year. This year's Newbery honor books are: "Ramona Quimby, Age 8" (Morrow), written by Beverly Cleary and illustrated by Alan Tiegreen; and "Upon the Head of the Goat: A Childhood in Hungary, 1939-44" (Farrar, Straus) by Aranka Siegal.

"A Visit to William Blake's Inn" also became the first Newbery winner to be named as a Caldecott honor book. The others are: "Where the Buffalos Begin" (Warne), drawings by Stephen Gammell, written by Olaf Baker; "On Market Street" (Greenwillow), illustrated by Anita Lobel, words by Arnold Lobel, who last year won the Caldecott Medal for "Fables"; and "Outside Over There" (Harper & Row), illustrated and written by Maurice Sendak, a medal winner in 1964 for "Where the Wild Things Are."

The Newbery Medal was first given to Henrik Van Loon for "The Story of Mankind" in 1922. It was named for John Newbery, an 18th-century English publisher and friend of Samuel Johnson. Recent winners have included Katherine Paterson (1981, 1978), Joan W. Blos and Ellen Raskin. The Caldecott Medal, named in honor of 19th-century British illustrator Randolph Caldecott, has been awarded annually since 1938.

The winners will receive their medals at the ALA's annual conference in July.