It's not a sign, but this interesting mirror at the top of the hill in Mystic gives a good view of the sky.
{"Image Make": "Canon", "Image Model": "Canon EOS REBEL T1i", "Image XResolution": "240", "Image YResolution": "240", "Image ResolutionUnit": "Pixels/Inch", "Image Software": "Adobe Photoshop Lightroom 5.3 (Windows)", "Image DateTime": "2014:05:04 19:42:44", "Image YCbCrPositioning": "Centered", "Image ExifOffset": "224", "EXIF ExposureTime": "1/400", "EXIF ExposureProgram": "Aperture Priority", "EXIF ISOSpeedRatings": "100", "EXIF ExifVersion": "0230", "EXIF DateTimeOriginal": "2014:05:04 14:00:13", "EXIF DateTimeDigitized": "2014:05:04 14:00:13", "EXIF ComponentsConfiguration": "YCbCr", "EXIF ApertureValue": "6", "EXIF ExposureBiasValue": "-2/3", "EXIF MeteringMode": "CenterWeightedAverage", "EXIF Flash": "Flash did not fire, compulsory flash mode", "EXIF FocalLength": "50", "EXIF FlashPixVersion": "0100", "EXIF ColorSpace": "sRGB", "EXIF ExposureMode": "Auto Exposure", "EXIF WhiteBalance": "Auto", "EXIF SceneCaptureType": "Standard", "EXIF LensModel": "EF50mm f/1.8 II"}