地理環境
山(shan)(shan)(shan)勢(shi)雄偉(wei),因位在群山(shan)(shan)(shan)的(de)(de)中(zhong)(zhong)央部位,站(zhan)在峰(feng)頂的(de)(de)瞭(liao)望(wang)塔上遠眺,視野極佳,四(si)周山(shan)(shan)(shan)巒盡入(ru)眼底,如(ru)東(dong)側的(de)(de)大(da)尖后山(shan)(shan)(shan)、磺嘴(zui)山(shan)(shan)(shan)、大(da)尖山(shan)(shan)(shan)、頂山(shan)(shan)(shan),西(xi)北(bei)的(de)(de)大(da)屯山(shan)(shan)(shan)、小觀(guan)音、竹子山(shan)(shan)(shan)連峰(feng),及西(xi)南的(de)(de)面(mian)天山(shan)(shan)(shan),而(er)淡水河由南向北(bei)蜿蜒(yan)至觀(guan)音山(shan)(shan)(shan)一(yi)帶的(de)(de)美景也歷歷可見。七星山(shan)(shan)(shan)是火(huo)山(shan)(shan)(shan)群諸峰(feng)中(zhong)(zhong)最晚噴發的(de)(de)一(yi)座,由噴出的(de)(de)熔巖流和(he)碎屑物(wu)在火(huo)山(shan)(shan)(shan)口周圍交互堆疊而(er)成,因此外形為標準的(de)(de)錐狀(zhuang)火(huo)山(shan)(shan)(shan),火(huo)山(shan)(shan)(shan)活(huo)動所留下來的(de)(de)地形遺(yi)跡:硫(liu)氣孔、溫泉露頭、斷層……皆十分明顯,其中(zhong)(zhong)以(yi)七星山(shan)(shan)(shan)北(bei)面(mian)鞍(an)部的(de)(de)小油(you)坑(keng)最具代表,小油(you)坑(keng)為火(huo)山(shan)(shan)(shan)爆發而(er)形成的(de)(de)硫(liu)氣爆裂口,地熱仍在不斷作用中(zhong)(zhong),終年(nian)熱流滾(gun)滾(gun)、煙霧蒸騰(teng),景觀(guan)殊異。
景觀
攀登七星山可由小油坑、冷水坑、中湖、苗圃等登山口進入,登山步徑明顯可見;其中以從小(xiao)油坑循(xun)石階步道登主峰較(jiao)不費(fei)力,約1小(xiao)時(shi)可抵山(shan)(shan)頂。由主峰步行約15分鐘抵東(dong)(dong)峰,東(dong)(dong)南麓(lu)山(shan)(shan)間凹地有(you)一(yi)(yi)潭水(shui)池,因(yin)地形(xing)之故,經(jing)常(chang)云(yun)霧縹(piao)緲,早年冬(dong)候(hou)鳥(niao)、小(xiao)水(shui)鴨(ya)常(chang)到此(ci)(ci)棲息,所以稱為(wei)“鴨(ya)池”,而(er)后則易名為(wei)“夢(meng)(meng)(meng)幻湖(hu)(hu)(hu)”。夢(meng)(meng)(meng)幻湖(hu)(hu)(hu)面(mian)積(ji)雖不大,但夏季時(shi)一(yi)(yi)泓碧(bi)水(shui)映著山(shan)(shan)樹,倒影柔麗(li);冬(dong)季時(shi)層層山(shan)(shan)霧凝(ning)聚湖(hu)(hu)(hu)面(mian),景(jing)致更(geng)加迷人。 湖(hu)(hu)(hu)底因(yin)饒富豐厚(hou)的(de)腐(fu)植(zhi)(zhi)土,因(yin)而(er)孕(yun)育出全世界獨一(yi)(yi)無二的(de)臺灣特有(you)種(zhong)植(zhi)(zhi)物——“臺灣水(shui)韭”。臺灣水(shui)韭是一(yi)(yi)種(zhong)水(shui)生蕨類,外形(xing)和韭菜很(hen)相似,葉片織細翠(cui)綠(lv),莖粗短,夢(meng)(meng)(meng)幻湖(hu)(hu)(hu)是世界唯(wei)一(yi)(yi)的(de)發現(xian)地,且是已知水(shui)韭類植(zhi)(zhi)物分布緯度最低的(de)地方,而(er)夢(meng)(meng)(meng)幻湖(hu)(hu)(hu)也因(yin)此(ci)(ci)列(lie)屬(shu)陽明山(shan)(shan)公園生態保護區(qu),然管制區(qu)僅限湖(hu)(hu)(hu)面(mian)四周(zhou),其他曲徑步道則可自(zi)由進出;從步道上瞭望夢(meng)(meng)(meng)幻湖(hu)(hu)(hu),如夢(meng)(meng)(meng)似幻的(de)湖(hu)(hu)(hu)景(jing)盡覽無遺(yi)。