Ever wonder what it feels like to cross the Bridge of Sighs, once Pittsburgh's ultimate perp walk?

That poetic, rusticated granite arch between the Allegheny County Courthouse and its former jail will be among the sites explored from 1 to 5 p.m. next Saturday when Louise Sturgess and Karen Cahall of the Pittsburgh History & Landmarks Foundation lead a walking tour of two Downtown landmarks -- the courthouse (and former jail) and the City-County Building.

Tour-goers will visit locations not often seen by the public, including the restored Courtroom 321 and the Bridge of Sighs, as well as the Jail Museum and former warden's house. They'll also tour Council Chambers and the Jury Assignment Room in the City-County Building and hear about plans for a green roof on the County Office Building Annex.

City Clerk Linda Johnson-Wassler and Darla Cravotta of County Executive Dan Onorato's staff will greet and meet with tour participants. Al Tannler, Landmarks' historical collections director, will speak about Henry Hobson Richardson, architect of the Allegheny County Courthouse and former jail. Ed Urban, the jail's retired deputy warden, will open the Jail Museum and discuss the exhibits.

Space is limited; e-mail reservations to Mary Lu Denny, marylu@phlf.org. Meet at the Richard Caliguiri statue, City-County Building, 414 Grant St., Downtown. Fee: $20, $10 for students or Landmarks members.

-- Patricia Lowry, Post-Gazette architecture critic

Every third Tuesday of the month, starting this Tuesday, West Overton Museums in Scottdale will hold an antique appraisal session with appraiser John Mickinak from 7 to 9 p.m.

He will value glass, ceramics, costume jewelry, some coins, documents, decorative arts, furniture and clothing. Cost is $15 for the first three items and $6 for each additional item up to five total. To make a reservation or find out if your items can be appraised, call 724-887-7910 (www.westovertonvillage.org).

Doug Oster, the PG's Backyard Gardener columnist, will discuss vegetable gardening at 10 a.m. next Saturday at Peters Township Public Library. Afterward, he will sign copies of his new book, "Tomatoes Garlic Basil: The Simple Pleasures of Growing and Cooking Your Garden's Most Versatile Veggies" (St. Lynn's, $18.95).

Arhaus Furniture stores in Shadyside and Pine will hold free decorating seminars on Thursday and March 21. "How to Design a Room" is the topic of the two-hour sessions.

The Shadyside seminar will begin at 6 p.m. Thursday at the store, 235 S. Highland Ave. (412-362-7005) The Pine seminar is at 10 a.m. next Sunday at 12075 Perry Highway (724-934-5390). Call to reserve a seat.

"Human Health and the Environment," a workshop on common toxins and their effect on people, will be held from 6:30 to 8 p.m. April 8 at the East End Food Co-Op. It is sponsored by the Pennsylvania Resources Council and UPCI Center for Environmental Oncology.

The cost is $20 per person or $25 per couple. To register, go to www.prc.org or contact call Sarah Alessio at 412-488-7490 ext. 236, or saraha@ccicenter.org.

Rain barrel/watershed workshops are scheduled through June by the Pennsylvania Resources Council. Participants learn how to make a rain barrel from a 55-gallon drum (not supplied) and receive the hardware. Cost is $35 per person or $45 per couple. All begin at 6:30 p.m. unless otherwise indicated. For information and/or to register, contact Nancy at 412- 431-4449, ext. 247, or nancym@ccicenter.org (www.prc.org).

The schedule:

April 15: East End Food Coop, Point Breeze

April 22: Richland Municipal Building

April 29: Three Hierarchs School, Heidelberg

May 6: Upper St. Clair Library, 7 p.m.

May 15: Schrader Environmental Center, Wheeling, W.Va. 10 a.m.

May 19: Regional Environmental Education Center, Upper St Clair, 6 p.m.

May 27: Phipps Garden Center, Shadyside, 7 p.m.

June 2: Lauri Ann West Memorial Library, O'Hara, 7 p.m.

June 13: Hahn Nursery, Ross, 2 p.m.

Doug Oster writes a blog, "Growing With Doug," exclusively at PG+, a members-only web site of the Pittsburgh Post-Gazette. Our introduction to PG+ gives you all the details.