The only known conservatory in the world built with no glass (only wood lath) is located in San Diego's Balboa Park. Balboa Park's history dates back to 1868 but it wasn't until city leaders, planning for the First World's Fair: The 1915-16 Panama-California Exposition, that Balboa Park and many of its modern-day tourist attractions, including the Botanical Building, were built. The Botanical Building is also one of the largest lath structures in the world.

According to author Richard Amero, Alfred D. Robinson, the founder and president of the San Diego Floral Society, suggested the building of the lath house as a featured part of the Exposition, which was planned to open to the public on January 1, 1915. The primary designers of the architectural plans for the Exposition, architects John C. Olmsted and Bertram Goodhue, did not originally have plans for such a unique structure. Olmsted, and Irving Gill, another architect brought on to assist in the planning, liked the idea but it wasn't until Robinson wrote down a dream that he had one night, that the plans for the Botanical Building really took shape.

He said, "We were in the largest lath house ever projected as a pleasure resort. Where the band played and we sat was a great central dome, 500 feet in diameter, arched over by a domed roof rising fifty feet in the air. Up its supporting columns ran choice vines, jasmines of such sweet savor, begonias and tecomas of gaudy hue and the curious Dutchman's pipe. Palms from many lands and of many forms lined the borders and were in beds here and there while begonias and other foliage plants nestled at their feet. In the air hung orchids with their strangely beautiful blossoms.

From this central court ran out six great arms or aisles and in each were gathered and growing in graceful harmony a great family of plants. There were thousands and thousands of varieties and each was plainly labelled. The lighting had been carefully planned so as not to strike the eye offensively and the whole effect was absolutely entrancing."

Goodhue and Director-General of the Exposition, D.C. Collier and Director of Works, Frank P. Allen are all credited, along with Thomas P. Hunter, a structural engineer, with having had a hand in the shape the Botanical Building was built in, this was a departure from the original plans for the building, which had first been conceived as a Spanish- Renaissance palace.

Excavations for the Botanical Building began in August 1913; the steel arrived in November. In July 1914, it was reported by the San Diego Sun newspaper that the Botanical Building was complete. "The largest lath house in the world" measured an impressive 250 feet long, 75 feet wide and 60 feet tall. The entrance was formed by five arches. Two of which, on the left and the right, were crowned by octagonal-shaped Persian-style domes. The three intervening arches were originally enclosed by glass panes that separated into horizontal and vertical sash panels. Redwood dowels later replaced the glass panes during a 1957-59 renovation.

The top middle section of the Botanical Building is separated from the side wing barrel vaults by a large arch that surrounds straight vertical laths. This arch is topped by a dome, which is crowned by a graceful open cupola. The vaults and dome are held together by steel trusses that support 70,000 feet of curved redwood lath that follows the shape of the building.

Paul Thiene, the Superintendent of Landscaping, began preparing the plants to be transplanted to the Botanical Building as early as 1912. Most of the plants: palms, bamboos, Aralia chabrierii and Aralia elegantissima, and banana trees, were not potted by grew from subsoil. Birdcages were hidden among the larger plants and trees and contained canaries, linnets, and thrushes. The plants were watered by hand and by overhead pipes containing spray nozzles.

In 1915, as editor of the California Garden publication, Alfred Robinson wrote, "Let us be thankful for our Horticultural [Botanical] Building. With that title it could hardly be a true lath house, but let us think of ten acres under a lathed-in pergola, partly on the flat, partly going in steps down into a canyon, lighted cunningly as with fireflies, and let us think hard enough to bring the reality before some other place seizes the idea and reaps the reward of originality." This leads us to conclude that Robinson was not truly happy with how the building turned out. And, as Richard Amero also points out, "Anyone who has visited the many conservatories in the United States, like the Conservatory in Golden Gate Park, San Francisco, the Conservatory in Garfield Park, Chicago, the Conservatory in Como Park, Saint Paul, and the Climatron at the Missouri Botanical Garden, St. Louis, must experience a letdown when they are inside the Botanical Building. Gardeners are conscientious and knowledgeable about plants, but they are constrained by the size of the building, by the many potted plants that have to be taken out as blooms fade, and by the unruly nature of plants that periodically burst through the roof.

Mildew, termites and rust are perpetual problems. Pigeons are a nuisance as are --- though the gardeners might not like to say so --- people who are continually taking away plants by the roots and as cuttings." [Apparently and sadly, visitors are known to steal plants from the pots they grow in.]

However, even though it has its limitations, San Diegans continue to want to keep the Botanical Building. It was renovated in 2002 at the cost of ten times its 1915 cost and eight times its 1957-59 cost! The San Diego Botanical Building continues to be a huge "must-see" destination for visitors to San Diego. There are 2,100 permanent plants on display. Included in the display is a fun, just-for-kids, area that features a "Carnivorous Plant Bog", with Pitcher Plants and Venus Fly Traps. There are also "Touch and Smell Gardens" that have unusual varieties of plants that feature special aromas such as chocolate and lemon mint.