Valente did not re- develop the lot when an apartment was torn down in 1986 after being deemed a neighborhood hazard.

Once Uribe began his weeding, the idea of having a park in the community took hold.

In 1993, neighborhood residents began to plant beds of flowers. Over time they added gravel walkways, benches and even a small pond.

Currently the park is home to a sculpture bench entitled "Freedom Bench," donated by prominent New England sculptor Ayls Meyers.

Students at the King's Open Elementary School and the Martin Luther King School, both in Cambridge, also use the park for educational purposes.

They have painted murals on the park's fences and have observed its biologically diverse habitat- a unique find in the middle of a bustling city- for their classes.

They are also working on science projects there in conjunction with the American Museum of Natural History in New York City.

The lot's function as a teaching tool extends to a national level, too: as part of a project called Journey North, students have planted tulip bulbs in the park. They will watch them grow and compare notes with other students via the Internet, documenting the coming of spring up and down the East Coast.

In a March 10 letter written to Richard and Elizabeth Valente, King School Principal Joseph E. McKaigue emphasized the important role that the park had begun to assume in the education of his students.

"The school has no green space and over the last two years, students have undertaken science and technology projects at the park," McKeigue wrote.

"These current projects are just a sign of the potential for such unique site," he added.

Last year 35 students learned and worked in Putnam Park, and next year, teachers had planned to involve more than 80 students.

But all that may change.

The Sale

Now, an undisclosed developer has bought the park, and its future is uncertain.